What we would like you to do is to find a topic from this week's chapter that you were interested in and search the internet for material on that topic. You might, for example, find people who are doing research on the topic, you might find web pages that discuss the topic, you might find a video clip that demonstrates something related to the topic, etc. What you find and use is pretty much up to you at this point. Please be sure to use at least 3 quality resources. If you use videos, please limit it to one video.
Once you have completed your search and explorations we would like you to:
1a) State what your topic is.
1b) Discuss how the topic relates to the chapter.
1c) Discuss why you are interested in it.
2) Next, we would like you to take the information you read or viewed related to your topic, integrate/synthesize it, and then write about the topic in a knowledgeable manner. By integrating/synthesizing we mean taking what your read/experienced from the internet search organize the information into the main themes, issues, info, examples, etc. about your topic and then write about the topic in your own words using the information you have about the topic.
Synthesizing information is hard for some people to do - many students write what we refer to as "serial abstracts." They are tempted to talk about the websites rather than the topic proper Serial abstract writers will talk all about website #1, start a new paragraph and talk all about web site #2, start a new paragraph and talk all about web site #3, and then write some kind of conclusion about the three websites they used. Serial means one after the other...again, this is what you DON'T want to do! We want you to talk about the topic, not the websites!
Also, if all three sites are on the same one topic it will be easier.
At first it is a real challenge to get out of the habit of writing "serial abstracts," but we assure you once you get the hang of it writing about the topic is much easier to do using the integration method. And besides this is the way researchers and scientists write their technical reports and findings - many of you will have to be able to do this for other classes and for jobs that you may eventually be hired for so now is a good time to learn this skill.
At this point don't worry so much about a grade, worry about doing your best to have fun with the topic and then integrate it into your own words to share what you found and what you now know.
At the end of your post, please include working URLs for the three websites. For each URL you have listed indicate why you chose the site and the extent to which it contributed to your post.
1a) State what your topic is.
Eidetic imagery
1b) Discuss how the topic relates to the chapter.
Eidetic image, a vivid subjective visual phenomenon. An eidetic person claims to continue to “see” an object that is no longer objectively present. Eidetic persons behave as if they are actually seeing an item, either with their eyes closed or while looking at some surface that serves as a convenient background for the image. Also, eidetic persons describe the image as if it is still present and not as if they are recalling a past event.
This chapter was about the eye and how they perceive and process information. I was curious about special cases and so on, this happens to tie in with memory recall, which interests me.
1c) Discuss why you are interested in it.
This has always been interesting to me. I hope a way to attain some sort of memory even close to eidetic imagery is on the horizon, it would make things a whole lot easier as far as schooling, most higher level jobs, and just day to day things, like what to get at the grocery store so your girlfriend doesn't yell at you when you get home.
2) Take the information you read or viewed related to your topic, integrate/synthesize it
Eidetic imagery, Eidetic memory, photographic memory, total recall, ect. is the ability to recall images, sounds, or objects in memory with extreme accuracy. Eidetic memory as observed in children is typified by the ability of an individual to study an image for 30 seconds, and maintain a nearly perfect photographic memory of that image for a short time once it has been removed. Although many adults demonstrate extraordinary memory abilities, it is unknown whether true eidetic memory can persist into adulthood.
While people with photographic memory will very precisely recall visual information, a person with eidetic memory could potentially recall other aspects of the event including sensory information that is visual, auditory, tactile, gustatory, and olfactory, as well as other dimensions. Some people who generally have a good memory claim to have eidetic memory. However, there are distinct differences in the manner in which information is processed. People who have a generally capable memory often use mnemonic devices to retain information while those with eidetic memory remember very specific details, such as where a person was standing, what the person was wearing, etc. They may recall an event with greater detail while those with a different memory remember daily routines rather than specific details that may have interrupted a routine. However, this process is generally most evident when those with eidetic memory make an effort to remember such details.
Resources:
http://eideticimagepsychology.com/what-is-an-eidetic-image/
This website explains eidetic imagery pretty well, it even explain how one can view and eidetic image.
http://en.wikipedia.org/wiki/Eidetic_Imagery
I found this website really interesting because it gives many distinctions between eidetic imagery and other forms of memory or imagery.
http://www.slate.com/blogs/quora/2013/07/18/what_is_it_like_to_have_a_photographic_memory.html
I really liked this article because eidetic imagery is described from someone who has it, and they like all of the pros and cons of having such an ability.
I find the topic of eidetic memory to be fascinating! Eidetic memory would come in great handy when memorizing for tests, etc. I also like that you talked about the differences between photographic memory and eidetic memory, because they are very similar yet have distinct differences. Overall, your paper had a very nice flow, and you didn't just put sources one right after the other, so that was very nice. I also noticed that you used fairly good sources (although the last link didn't work). So, just keep up the great work!
The topic I choose to do more research on was macular degeneration and scotomas. Scotomas typically accompany macular degeneration. Aging-related macular degeneration is discussed in the topic along with scotoma. In addition, this chapter discusses the physical makeup of the eye and its functions and a scotoma creates a blind spot within our vision, and macular degeneration physical affects the macula and therefore our vision. My main focus was on scotomas. I was interested in this topic because the visuals in the book caught my eye and because it is apparently something everyone may experience as they age, I thought it would be good to find out more about it.
There is a general consensus between my sources that a scotoma is a blind area in our visual field that can occur in the center as an enlargement to our already present blind spot (optic disc), or in any other area of the eye. Scotoma also varies in size, and can be black or just less vivid areas in the visual field. Wikipedia states that all mammals have the optic disc area within their eye where a small but usually unnoticed blind spot is due to a lack of photoreceptor cells, and the passage of optic nerves etc.
There are several causes to the presence of scotomas. One, mentioned in the book and several sources is macular degeneration. However, diseases and brain damage can also lead to the development of a scotoma. Some diseases or health problems that may cause a scotoma that were listed are, hypertension, tumors of the eye, pituitary gland or brain, glaucoma, fluid in the eye, and sometimes drugs. Because some forms are caused by tumors or other illnesses that cause swelling, they can sometimes be fixed after surgery is done to cure the problem.
In order to diagnose a scotoma doctors do a visual field test. This allows them to create a virtual map of your visual field for each eye. The machines that do this can detect where your visual field contains a scotoma and how large it is. Previous to the test your own already present scotoma is mapped. A study was done on new technology in 2005 that helped to differentiate between types of scotomas found in different forms of macular degeneration. They found the development of scotomas within the different types followed a general pattern, which may help in predicting, evaluating, and watching scotoma development in patients with aging-related macular degeneration.
Sources Used:
1. http://en.wikipedia.org/wiki/Scotoma
2. http://www.sw.org/HealthLibrary?page=Scotoma
3. http://www.ncbi.nlm.nih.gov/pubmed/15933591
Terms Used:
1. I choose this website for a general jumping off point to have a general definition and basic knowledge on scotomas. I used it mainly to aid in defining terms and comparing it’s information to the other sites.
2. This website I used to get a viewpoint from the health field. It included more in depth knowledge about known diseases, and diagnosis of scotomas as well as defined what the condition was.
3. This final website was a study done on new technology which I thought was important to include, but it did not contribute a lot of definitions or anything like that to my post.
Terms Used: macular degeneration and scotomas, Aging-related macular degeneration, blind spot, macula, eye, vision, visual field, optic disc, photoreceptor cells, optic nerves,
I found your topic of scotomas to be of great interest, especially since it's likely to affect many of us as age. I had no idea there are so many diseases that cause scotomas. As I was reading, I was curious as to whether this would affect one from renewing his/her license? There was a nice flow to your paper, and you did a great job at citing sources. Your sources were credible, which I can appreciate. In future assignments try to give more detail. What else don't we know about scotomas...what else does research say? Otherwise, great job!
I chose to do further research into Dyslexia (also Scotopic Sensitivity Syndrome). for those of you who don’t know Dyslexia is a reading disability, often categorized as a hidden disability. Quite often children with dyslexia are placed in “special” reading and writing classes, because their reading, spelling, and handwriting are often well below their academic year. The dyslexia can go undiagnosed for many years, sometimes not properly diagnosed until middle school age.
I am dyslexic and my dyslexia went undiagnosed until i was in 6th grade. My spelling ability is severely impeded, but due to Auto Correct, Dragon Software, and Spell Check i only make a few mistakes. Take the previous sentences from start to this one, I have made 28 spelling mistakes, which i will go back and fix now, but the only reason i know this is due to the spell check on my computer.
Since being diagnosed with dyslexia allot of dores were opened to me to help me with my education and personal life. One major thing that helped me through all the reading in high school english classes were Audiobooks. When it takes me about 2 months to read a book that i am actually interested in, keeping up with a class reading The Great Gatsby, Romeo & Juliet, or To Kill a Mockingbird is almost impossible. But thanks to Audio books, and my school district who had a total of 19 kids with dyslexia, they payed for a school district wide subscription to WILBOR (West/Central Iowa Libraries Building Online Resources), which has a FREE Audiobook checkout option. I also use some other accommodations that i will discuss a little later.
Now allot of people think first off that dyslexia only applies to words, this is false. Second misconception, that dyslexics see words backwards, false also (though it can sometimes happen like that). As to the first point, dyslexia not only applies to written words, but to Numbers, Left & Right, Verbal, ASL Hand Gestures, and a number of other things. As to the mirroring of words, the there are many ways a dyslexic could possibly see one sentence. They can see rivers, swirls, seesaws, piled letters, or just the letters in the wrong order. Take the sentence “The quick brown fox jumped over the lazy dog” i could see that at first glance as “Heq tckie fox bromn pmjued the vero alny dog”.
Now comes the other accommodations that i mentioned. One of my favorites being Scotopic Overlays. They are quite honestly a transparent colored plastic that you can put down on a page and they clear things up a bit for a dyslexic person. Letters don’t seem to move or twist as much. When these overlays were empirically tested with dyslexic and normal readers “While normal readers ... improved an average of 2.5 months, dyslexics improved an average of 1.2 academic years in reading ability. All but 2 dyslexics... improved-a range of 2 months to 3 full academic years”.
Why would a colored transparency make such a difference in reading ability? The best way to describe this would be to say that the reason the letters move for dyslexics and those with Scotopic Sensitivity Syndrome, though not proven yet, it is theorized that it is due to an incomplete light wavelength. Our eyes perceive that something is missing, and i personally like to think that that something missing is like the glue that holds the letters to the page.
I mentioned Scotopic Sensitivity Syndrome, this and dyslexia are often linked, because dyslexia and SSS are “visual perceptual disorder which can affect a person's ability to read”. One article went on to explain “Black text presented on a white background can be difficult to read, especially on glossy paper. Text can appear to swirl, blur or move around making individual words and letters difficult to perceive. Other symptoms can include a sensitivity to glare, which can lead to headaches and fatigue, and poor depth perception”. The best visual representation i have for this is a scene in The Lightning Thief, where Percy Jackson’s teacher asks him to read what is on the board and he can’t because it spins and warps.
*Side Note: The Movie is NOTHING like the book, and i recommend the book as it is my favorite series ever. (yah i am a dyslexic who loves to read)
Sources
http://web.b.ebscohost.com/ehost/detail/detail?vid=9&sid=27b341ea-b6ec-4279-9d13-ab6bfef190c6%40sessionmgr115&hid=106&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=psyh&AN=1999-95010-116
http://www.bltt.org/dyslexia/scotopic.htm
Percy Jackson & the Olympians: The Lightning Thief(2010)
Danny, I am so impressed. You did an absolute wonderful job at explaining not only what Dyslexia is, but also discussing what the challenges you and others face...that I think people don't really think about. In your intro, you mentioned how you had incorrectly spelled 28 words. That was powerful...I think about how difficult it would be to have dyslexia and not have some of the tools like auto-correct and others that you mentioned. Not only that, but the time it would take to read a book just for leisure..let alone a book for school. I like that you used more research to back up some of your claims. In your next post, try to use a little more research, but in this case, you have firsthand experience with Dyslexia. Wonderful, Wonderful job!
The topic I am choosing to research and write about this week is peripheral vision. This topic caught my eye after reading the section about the man who could not see the stars. This was a story of a man, who for many years, went out to the country to look up at the stars. He would find is “special” star that he had found years earlier, and each time he would go to the country, it was his mission to find that star. He would scan the night sky, and once he found that “special” star he would simply turn his head and let his peripheral vision system take over. He could see that star better with his peripheral vision than he could by focusing on that one star. On a visit he had just two years later, he could not find that star in his peripheral vision. This was the final straw that made him visit his ophthalmologist. He was having difficulty when driving at night and he could not judge distances very easily anymore.
There are many causes of peripheral vision loss. A common cause of loss of peripheral vision (also called a peripheral field defect) is optic nerve damage from glaucoma. Eye "strokes" (occlusions) that block normal blood flow to the eye's internal structures, including the optic nerve, also can lead to loss of peripheral vision. Finally, a stroke or injury also may damage portions of the brain where images are processed, leading to blind spots in the visual field. Some of the basic causes of peripheral vision loss include: Glaucoma, Retinitis pigmentosa, eye strokes or occlusions, detached retina, neurological damage such as from optic neuritis, compressed optic nerve head (papilledema), and concussions (head injuries). The book did not give other causes to this type of defect in the peripheral vision. The book had only mentioned Retinitis Pigmentosa which is a family of hereditary diseases by the progressive death of photoreceptors and degeneration of the pigment epithelium.
Surprisingly enough we all have low visual acuity (resolution) in parts of the visual field that are not at the center of gaze. We are not aware of this because we instinctively direct our center of gaze to where we are looking. The center of gaze, called the fovea, has a higher density of cones than anywhere else on the retina. In fact, at the fovea, there are no rods at all. The fovea evolved to have the highest possible visual acuity, and the cones are as small as they can possibly be and still function. Moreover, in the fovea, the retinal ganglion cells have smaller receptive fields, and in the periphery, they have much larger receptive fields. Interesting enough humans have the least amount of visual power in our peripheral vision system. The fact that our vision has the highest acuity in the center of gaze does not mean that our vision in the rest of the visual field is inferior; it’s simply used for different things. Foveal vision is used for scrutinizing highly detailed objects, whereas peripheral vision is used for organizing the broad spatial scene and for seeing large objects. Our foveal vision is optimized for fine details, and our peripheral vision is optimized for coarser information. I thought it was interesting to read about the tests people use to measure their peripheral vision.
Going back to the first paragraph, there are many defects of our peripheral vision system. Although there is no cure for these diseases/defects, there are ways to lessen the chances of developing them. Various doses of Vitamin A and E can alter the potential of effects of RP. Not only are their vitamins we can take, there are also many eye exercises we can do on our own. Many parents are presenting these exercises to their children. It not only helps prevent eye disorders, but it can strengthen their eye muscles and vision. Visual processing skills like tracking, eye teaming, and visual perception are developmental skills that all children need in addition to seeing clearly. If these skills don’t develop normally, children can struggle with demanding visual tasks like reading. Each year as print gets smaller, school performance drops, and as visual fatigue sets in, children become easily frustrated and distracted. All too often, these children appear to have a learning disability or attention problems when the real culprit is poor visual processing skills.
One important aspect of this chapter has helped me understand that knowing how our eyes work and what defects or diseases we can get early or later in life is very important. If I can educate myself and look for the warning signs in my children, I can perhaps alter what vision tests can be done to detect these disorders early enough for some kind of treatment.
References:
http://www.allaboutvision.com/conditions/peripheral-vision.htm
http://www.webexhibits.org/colorart/ag.html
http://www.eyecanlearn.com/#Peripheral
TERMS: peripheral vision, peripheral field defect, optic nerve tract, glaucoma, retinitis pigmentosa, eye strokes, occlusions, detached retina, optic neuritis, papilledema, fovea, rods, cones, ganglion cells, receptive fields, foveal vision, tracking, eye teaming, visual perception
Sorry I forgot to give explanation about the sources I used for this blog post!
http://www.allaboutvision.com/conditions/peripheral-vision.htm
I chose this site because it gave me more than just one disorder our eyes can develop. It gave me more insight to our peripheral vision.
http://www.webexhibits.org/colorart/ag.html
I chose this site because it gave very detailed diagrams of our eye and what cells do what in that process.
http://www.eyecanlearn.com/#Peripheral
I chose this website to learn about the exercises parents can give their children and also knowing more about preventing the disorders.
Wow! You did a wonderful job at explaining peripheral vision. Your paper also had great structure, and I think it was good that you made it clear that Foveal vision isn't necessarily better than peripheral vision...they're just used for different things. You got me thinking how much we actually use our peripheral vision. We never stop and think about these topics, when we use it everyday. I enjoyed reading your paper, and keep up the great work!
I chose the topic of age-related macular degeneration (AMD). In this chapter we learned about the eyes, how we perceive light and images from a biological standpoint. AMD was a topic in the chapter discussing how vision deteriorates and can eventually lead to blindness. I wanted to learn more about how AMD occurs and progresses. For me personally blindness would be very difficult to accept. I think that this is especially true later in life as this disease tends to occur.
AMD is a fairly common condition. It affects close to 15 million Americans and estimated that 200,000 are diagnosed each year. It is thought to generally occur in adults in their 50’s and 60’s. It is believed that it can be hereditary but that there are many cases with no familial history.
There are two types of AMD, dry and wet. Early and intermediate AMD are considered the dry, while late or advanced is wet. The difference is that in the dry drusen (tiny yellow or white accumulations of extracellular material under the retina), very early on the individual may have no loss of sight and it is only detected by an eye exam. As it progresses there is a breakdown of light sensitive cells in the macula, this causes vision loss. The wet stage there is the growth of abnormal blood vessels that leak fluid and blood. This can lead to swelling and damage to the macula. It is often fast moving and severe.
Along with being hereditary there are certain factors that make someone more at risk. The top four that appear most often are: smoking, lack of exercise (which is also a treatment), high cholesterol and poor diet (doctors advise a diet with a lot of green leafy vegetables…bad news for supertasters!) Diagnosis can be made before any vision loss has occurred, therefore it is recommended that people have regular check-ups with their eye doctors.
Treatment of AMD varies by stage, early AMD has no treatment, other than recommending a vision exam yearly and of course preventive measures like exercise, eat healthy etc. In intermediate the National Eye Institute recommend high dose of certain vitamins, (vitamin A, C, E, beta-carotene, zinc and copper) this can reduce vision loss by 25%. In advanced stages injections can be used to slow progression as can photodynamic therapy, which is when they inject a drug called verteporfin into the arm of the patient, and then shine a laser into the eye to activate the drug in the new abnormal blood vessels and sparing normal ones. The drug closes off the new blood vessels and slows their growth which slows vision loss.
There is no cure for AMD but it is good to know that there are a lot of treatments available to slow the progression. Early detection is best as is living a clean healthy lifestyle. It is rare for patients with AMD to lose all of their vision, which is good to know. I also found it interesting that this condition is onset without pain or discomfort. In my research I found no instance that mentioned pain associated with AMD. That is rather scary and really emphasizes the need for regular check-ups.
https://www.nei.nih.gov/health/maculardegen/armd_facts - This site had a lot of information written in layman’s terms about all aspects of AMD
http://www.webmd.com/eye-health/macular-degeneration/age-related-macular-degeneration-overview?page=4 - This site was broken up into categories like what it is, diagnosis, treatment and outlook, it had good information on treatment and expectations for those with AMD.
http://www.amd.org/ - This site is all about AMD, it is set up for patients and families. They had some good information about treatments and outcomes of treatments
Terms: AMD, vision, macula, retina,
From what I read, you are a good writer. Your paper had nice structure, and each paragraph built on from each other. It's interesting to see that 15 million people are affected with AMD...it means many of us may have to deal with this unfortunate disease. I think as young people, we often take vision for granted. Overall, absolutely wonderful paper. Thank you for sharing!
1. A) Retinitis Pigmentosa (RP)
B) This topic relates to the chapter because it is about people who have difficulty with their vision, specifically their peripheral vision and also under low light.
C) I am interested in this topic mostly because the story about the man who could not see the stars caught my attention.
2. There are about 100,000 people in the United States that have RP. This is due to genetic mutations. RP will be found in genes and runs in the family. This gene will be abnormal.The gene will be passed to a parents offspring by one of three different genetic patters such as, autosomal recessive, automosal dominant, or X-linked. RP happens because photoceptor cells die. This is a progressive disorder. The rate of progression and the loss of vision will vary from person to person.
There are many symptoms that may appear. Night blindness tends to be the first and most frequent. There is also reduced field vision, floaters and flashed, diminishing vision- specifically central, and color blindness will begin to happen through the progression of this disease. RP will usually be diagnosed when a person is in their adolescents or is a young adult. Also, there are different types of RP, usher syndrome, leber's congenital, rod-cone syndrome, Bardet-Biedl syndrome, and Refsum disease.
Although there is no known cure for RP, research is being done. Genetic testing is available at this time. Some research that is being done is in gene therapy and in different transplant options. Also, there are some ways a person could slow the progression of RP. A person could take vitamin A palmitate, but taking to much could be dangerous. It is also important for them to wear sunglasses in order to protect the retina.
Terms: Retinitis Pigmentosa, Vision, Peripheral Vision, Genetics, Photoceptor Cells, Genetic Mutation, Autosomal Recessive, Autosomal Dominant, X-Linked, Retina
https://www.youtube.com/watch?v=_puhRElL6Rg
This site was useful because it listed the symptoms of RP and had shown many examples of how someone would see something compared with someone with normal vision.
http://www.blindness.org/retinitis-pigmentosa
This site was useful because it explained what RP was and how it was inherited.
http://www.geteyesmart.org/eyesmart/diseases/retinitis-pigmentosa-treatment.cfm
This site was useful because it had different treatments for RP.
It was interesting learning more about RP...I can't believe 100,000 people are affected with it! Overall, you had very good structure and flow and you did a great job at incorporating the research into your paper. I wonder if there is more information we could have learned about RP? Overall, very good job!
Topic: Astigmatism
Astigmatism relates to the chapter because chapter 2 was all about the eye and our visual system. We learned about how our eyes perceive light and how our eyes take all of these different steps in order to adjust to the light and dark we are surrounded by.
I am interested in astigmatism because it is a topic that I know very little about but it is something that relates to what I have which is myopia. I am interested in learning more about astigmatism because it is another eye condition that many people have yet are unsure why they have it. Astigmatism is an eye condition that is caused by an eye that isn’t completely round. According to www.webmd.com nearly everyone has astigmatism. I knew that astigmatism was common but I did not know it was this common. What happens is when light enters the eye, it is refracted more in one direction than the other and because of this only part of the eye is focused. Although there is no known cause of astigmatism, it is associated with a misshaped cornea.
Astigmatism is actually fairly easy to diagnose and can be diagnosed by just having a simple eye checkup. Astigmatism can also occur with other vision problems such as myopia which is nearsightedness and hyperopia which is farsightedness. It is said that if you have blurry vision and that is associated with fatigue and eyestrain, you should go to the doctor to have it checked out. Astigmatism can be treated in different ways. One could get corrective lenses such as eyeglasses or contacts. Little did I know, there are different cases of astigmatism. One could have a more serious condition and one could have little astigmatism that wouldn’t even require corrective lenses. Irregular astigmatism would be a more serious condition and affects the cornea and can result in getting corneal procedures done. For those who have a “normal” condition of astigmatism refractive surgery is another option. This surgery is to change the shape of the cornea making it easier to see.
http://www.webmd.com/eye-health/astigmatism-eyes
http://www.aoa.org/patients-and-public/eye-and-vision-problems/glossary-of-eye-and-vision-conditions/astigmatism?sso=y
http://www.geteyesmart.org/eyesmart/diseases/astigmatism/
I also forgot to mention why I chose these website. I chose http://www.webmd.com/eye-health/astigmatism-eyes because I have used it in the past and it has always been a very reliable source. I liked how it listed all of the different sections out such as causes, treatments, symptoms, etc. It made it very easy for me to understand.
I used http://www.aoa.org/patients-and-public/eye-and-vision-problems/glossary-of-eye-and-vision-conditions/astigmatism?sso=y because it gave me even more detail than webmd but it was also still easy to understand.
I used http://www.geteyesmart.org/eyesmart/diseases/astigmatism/ because it gave me a really nice visual of the eye and it explained astigmatism through the picture. I like visuals because it makes it easier to understand what I am trying to learn.
I love the topic you chose, because I also have astigmatism. I didn't know the causes were unknown. The eye is fascinating...that if not all parts are perfectly aligned, it can impair our vision. For future assignments, try to go into more detail about your topic. Overall, nice job!
For my topic I chose to go over astigmatism. Astigmatism relates to the chapter because chapter 2 was about the function of the eye and our visual system. Chapter 2 briefly went over astigmatism and its effects on the eye. I’m interested in the topic because I personally have astigmatism in one eye, which makes me more interested in why I only have it in one eye.
Astigmatism is similar to nearsightedness and farsightedness. It basically is a refractive error, which means it is not an eye disease or a technical health problem, but a problem with how the eye focuses on light. Light fails to come to a single focus on the retina to produce clear vision. Instead of this multiple focus points occur, either in front of the retina or even behind it. The cause of it is irregularly shaped cornea. The cornea is supposed to have a symmetrical round shape. The meridian is supposed to be significantly more curved than the meridian perpendicular to it. Instead, eyes with astigmatism have steep and flat meridians. All of this related to the chapter.
There are actually three different types of astigmatism which I never knew. Myopic astigmatism is when one or both principle meridians of the eye are nearsighted. Hyperopic astigmatism is when one or both principle meridians are farsighted. Mixed astigmatism is when one principle meridian is nearsighted, while the other is farsighted.
It is diagnosed through visual activity, keratometry, and refraction. These tests are all done at an eye doctor visit. They help measure the cornea, measure the focus light, and measure visual acuity.
I found out that it’s more common in children than I thought. I developed astigmatism later in my teens so I assumed it probably wasn’t that common for children. But it turns out 28% of children have astigmatism.
Astigmatism can be treated using corrective lenses. This is actually something I almost got. But the fact that I only have it in one eye made it extremely uncomfortable for me. I was so used to using my old contacts that it bothered my left eye so much I could wear the astigmatism contacts. So to this day I still use my older contacts at a greater strength to overcorrect the astigmatism. I’m not entirely sure if this is a good method but my eye doctor hasn’t told me different. A person could also get refractive surgery to correct it.
URL: http://www.allaboutvision.com/conditions/astigmatism.htm
I chose this website because it went into detail about 3 different types of astigmatism.
URL: http://www.webmd.com/eye-health/astigmatism-eyes
I chose this website because it went into detail about what people with astigmatism can do.
URL: http://www.aoa.org/patients-and-public/eye-and-vision-problems/glossary-of-eye-and-vision-conditions/astigmatism?sso=y
I chose this website because it looked like it had pretty valid information that could help me understand more on the cause of astigmatism.
You do a great job at explaining some of the technical terminology. I also love that you were able to incorporate your life into the assignment. Great job! Next time, try to better connect the sources to one another. Other than that, great job!
For my topic I chose to go over astigmatism. Astigmatism relates to the chapter because chapter 2 was about the function of the eye and our visual system. Chapter 2 briefly went over astigmatism and its effects on the eye. I’m interested in the topic because I personally have astigmatism in one eye, which makes me more interested in why I only have it in one eye.
Astigmatism is similar to nearsightedness and farsightedness. It basically is a refractive error, which means it is not an eye disease or a technical health problem, but a problem with how the eye focuses on light. Light fails to come to a single focus on the retina to produce clear vision. Instead of this multiple focus points occur, either in front of the retina or even behind it. The cause of it is irregularly shaped cornea. The cornea is supposed to have a symmetrical round shape. The meridian is supposed to be significantly more curved than the meridian perpendicular to it. Instead, eyes with astigmatism have steep and flat meridians. Astigmatism occurs when the front surface of your eye (cornea) or the lens, inside your eye, has a slightly different surface curvature in one direction from the other. Instead of being even and smooth in all directions, the surface may have some areas that are flatter or steeper.
There are actually three different types of astigmatism which I never knew. Myopic astigmatism is when one or both principle meridians of the eye are nearsighted. Hyperopic astigmatism is when one or both principle meridians are farsighted. Mixed astigmatism is when one principle meridian is nearsighted, while the other is farsighted.
Your eye has two parts that focus images, the cornea and the lens. In a perfectly shaped eye, each of these focusing elements has a perfectly smooth curvature, like the surface of a smooth ball. A cornea or lens with such a surface curvature bends (refracts) all incoming light the same way and makes a sharply focused image on the back of your eye (retina). However, if your cornea or lens isn't evenly and smoothly curved, then it causes light rays to be unevenly focused. This causes a refractive error. Astigmatism is a type of refractive error. In astigmatism, your cornea or lens is curved more steeply in one direction than in another. You have corneal astigmatism if your cornea has a distorted shape. You have lenticular astigmatism if your lens is distorted. Either type of astigmatism can cause blurred vision. Blurred vision may occur more in one direction, either horizontally, vertically or diagonally. Astigmatism may be present from birth, or it may develop after an eye injury, disease or surgery. Astigmatism isn't caused or made worse by reading in poor light, sitting too close to the television or squinting.
It is diagnosed through visual activity, keratometry, and refraction. These tests are all done at an eye doctor visit. They help measure the cornea, measure the focus light, and measure visual acuity.
I found out that it’s more common in children than I thought. I developed astigmatism later in my teens so I assumed it probably wasn’t that common for children. But it turns out 28% of children have astigmatism. Astigmatism blurs your vision at all distances. Astigmatism is often present at birth and may occur in combination with nearsightedness or farsightedness. Often it's not pronounced enough to require corrective action. When it is, your treatment options include corrective lenses and surgery.
Astigmatism can be treated using corrective lenses. Contact lenses are also used in a procedure called orthokeratology. In orthokeratology, you wear rigid contact lenses for several hours a day until the curvature of your eye improves. Then, you wear the lenses less frequently to maintain the new shape. If you discontinue this treatment, your eyes return to their former shape. This is actually something I almost got. But the fact that I only have it in one eye made it extremely uncomfortable for me. I was so used to using my old contacts that it bothered my left eye so much I could wear the astigmatism contacts. So to this day I still use my older contacts at a greater strength to overcorrect the astigmatism. I’m not entirely sure if this is a good method but my eye doctor hasn’t told me different. A person could also get refractive surgery to correct it.
URL: http://www.allaboutvision.com/conditions/astigmatism.htm
I chose this website because it went into detail about 3 different types of astigmatism.
URL: http://www.webmd.com/eye-health/astigmatism-eyes
I chose this website because it went into detail about what people with astigmatism can do.
URL: http://www.aoa.org/patients-and-public/eye-and-vision-problems/glossary-of-eye-and-vision-conditions/astigmatism?sso=y
I chose this website because it looked like it had pretty valid information that could help me understand more on the cause of astigmatism.
Terms: Astigmatism, farsightedness, nearsightedness, refractive effort, eye disease, focus, light, retina, clear vision, focus points, cornea, meridian, myopic astigmatism, hyperopic astigmatism, mixed astigmatism, visual activity, keratometry, refraction, corrective lenses, lenses, refracts, keratometry, orthoketarology, frequency.
1a) State what your topic is.
Retinal Information Processing.(RODS and CONES)
1b) Discuss how the topic relates to the chapter.
This topic relates to this chapter because it explains how the visual field works, how certain information or sighting are processed into our brain to operate that part of the brain properly.
1c) Discuss why you are interested in it.
When i was in middle school, my mom had a surgery, that surgery went very well, and she didn't have to wear glasses anymore, at the time i didn't understand what was going on with her sighting, i also didn't ask alot of questions about it, but now that i've read this chapter, especially this section, i know that she had cataracts at a very young age, i believe it stated that most people who have cataracts are in their seventies or so, but when she got her surgery, she was either thirty four or thirty five. it makes sense to me now because the environment she grew up or spent half of her life in wasn't really anything to be compared to this environment that shes now in. I just want to understand how things like that work, and how i can understand my own visual problems.
2) find three sites and synthesize them
As i was reading this chapter, it made me curious about my own sight. i wear glasses because i am a near sighted individual, meaning i can only see things that are closer to me, things that are further from me seems blurry and out of focused, i would be myopia in this case. reading the research that was done on eight sight, and watching videos on it really made things more clear to me, literally. when i was in fifth grade, my mother had an eye surgery, at the time i didn't understand what was wrong with her but i now get it. she had an early emerge of cataracts. reading the chapter, reading from the sights, seeing examples about certain symptoms really had me understand what the conditions she was under were, which now makes more sense.
As it was stated in one of the studies, catatracks doesn't emerge until your later years, meaning when an individual is about seventy or so, but my mother got hers at the age of thirty four or thirty five. Because she was born and raised in Africa, she didn't come to the states till her late twenties, those conditions that she was in made it easier for her to attract that illness before she even ranched forty.
Rods are responsible to help you see in the dark, or somewhere that has low lighting, this would explain why animals like a dog, a cat or an owl see better at night. (only humans have rods and cones, other species only have one or the other). this explain why when you get into a theater or go somewhere dark for more than an you can see better because your rods got infracted and were activated like they should.
Cones however are meant for photopic vision, help you see in the bright. when you come outside and it's super sunny outside you glace at the sun with maybe one eye shut, this your chromophore is telling you that there's too much light and it can only process the appropriate amount of light for all the functions to working accordingly.
i think this is a very interesting section and it's very informative, i learned more reading this topic about the processing of retina than i've learned being in school all my life.
TERMS: Retina, cornea, visual system. cataracts, photopic, chromophore, cones rods, visual field
http://www.cis.rit.edu/people/faculty/montag/vandplite/pages/chap_9/ch9p1.html
This site gives you a description of cones and rods and how they work, it also gives you visual presentations to clarify what they are talking about.
https://www.youtube.com/watch?v=mEcmJDgzUcQ
as for this video, it’s a presentation of the whole diagram, it’s basically that section of the textbook put in a video labeled so you can understand where all the terms are really located in the retina, where the cones are at, where melanopsin , snaptic terminal etc .
http://www.intropsych.com/ch04_senses/retina.html
this is also a great website to take a peek at because this is actual study not only about cones and rods but also about the retina, which is like the mother of all this.
Great Great Work! Love learning more about this topic, and you do a nice job of applying this information to your life. Keep up the good work.
After reading chapter two the topic I chose to do further research on is the occurrence of cataracts. This topic relates to the chapter because it is directly related to vision and effects the crystalline lens which is an essential part of the eye and our general visual system. Generally the lens is transparent because the crystallines, a class of proteins, are packed together very densely and are considered to be regular. When something interferes with the regularity of the crystallines the lens will experience a loss of transparency. These transparencies of the lens are known as cataracts. I am interested in this topic because my great grandmother has cataracts and because there are an extensive amount of empirical studies linking cataracts to other medical phenomenon. I find it extremely interesting that deficits in the visual system can contribute to various serious diseases such as Parkinson's if it is not treated.
According to the National Eye Institute (NEI) there are four types of cataracts. The first is secondary that develops as a result of other eye surgeries or diseases such as diabetes. The second is a traumatic cataract that develops after the eye experiences trauma. The third is a congenital cataract that babies are born with. This type of cataract is usually severe and results in significant vision loss if treatment is not received. The last is called a radiation cataract that can result from certain types of radiation. It is vitally important to receive treatment to avoid permanent blindness.
An article by Hodge et al., examined the risks of not receiving cataract surgery within six months of diagnosis. They found marked evidence for their hypothesis that patient outcomes were worse if treatment was not received within six months of diagnosis. Patients who opted for surgery right away experienced better visual and quality of life outcomes as well as fewer experiences of adverse events such as falling or vehicle crashes. Patient satisfaction was also increased if surgery was performed within six months of diagnosis. This article exemplified the seriousness of this deficit and the importance of receiving cataract surgery to correct vision. Without treatment patients often experience large spots of permanent blindness.
Another article written by Lai et al., addressed the correlation between cataracts and Parkinson's disease. The results showed that participants with Parkinson's had a 1.48 fold increase in the occurrence of cataracts as compared to the non-cataract group. More specifically, patients with cataracts were found to have a 26% increased risk of developing Parkinson's disease. this article exemplifies the the risk of not receiving treatment for this deficit. I find it so interesting that a horrible disease such as Parkinson's could be related to a deficit in our visual system. The human body is connected in ways that we are still unable to fully explain. Doctors and researchers are currently working on more research to determine why a blind spot in our vision could contribute to the development of a life threatening disease. I love researching topics like these for class because I am able to look at many correlational studies that show significant evidence of a relationship between two things that you would never think are related.
Websites used:
http://crmcc.medical.org/clip/clip_research/docs/Hodge_the%20consequences%20of%20waiting%20for%20cataract%20surgery.pdf
http://web.a.ebscohost.com.proxy.lib.uni.edu/ehost/detail/detail?vid=3&sid=92c570ba-a2a9-462f-9a8b-7b8c29c76eb1%40sessionmgr4005&hid=4212&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=psyh&AN=2014-52759-001
https://www.nei.nih.gov/health/cataract/cataract_facts
Wow! You did a nice job of answering all of the questions in-depth. Also, you are a very good writer...and do a great job at connecting the sources to one another. Great job!
1abc) For my topic I decided to do further research on Age related macular degeneration or AMD. I did this because I always find learning about different diseases and abnormalities interesting and while reading this chapter that one grabbed my attention. I had never heard of this disease before so that also sparked my interest since it is one of the leading causes of vision loss in the elderly. After reading on the topic it motivated me to call my grandma, and sure enough that is why her vision is starting to go. Her kind is the dry form of AMD. So now knowing that it is in my family I wanted to see if I could find anything regarding genetics and if that had an influence along with a better explanation and an animation of it.
2)As we know from our reading there are two types of AMD, wet and dry. I will focus more on the dry form. From my research I found that Oxidative stress has an impact on the formation of AMD. Oxidative stress was something that I had no idea what it was so I just googled it and it is an imbalance between the systemic manifestation of reactive oxygen species (chemically reactive molecules containing oxygen) and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage. I also found that it is more prevalent in white females and you are at higher risk if a member in your family has it. Also people who smoke are twice as likely to develop it on their own than if they didn’t. There is no cure for AMD, but the key is management and regular checkups. Eye doctors can prevent or slow the progression of AMD if it is already present that’s why it is important to see the optometrist at least once a year. The main thing that causes AMD is a substance called drusen, which forms in the retinal pigment epithelium (RPE) layer of the eye. Drusen is a yellowish substance that pushes on the different layers in your eye causing damage slowly over time. That’s also why people do not notice it until it has done too much damage. The drusen can be spotted by your eye doctor and if noticed early on prevention steps can be taken so it does not further develop into wet AMD and make vision worse.
1) Barnett, B. P., & Handa, J. T. (2013). Retinal microenvironment imbalance in dry age-related macular degeneration: A mini-review. Gerontology, 59(4), 297-306. doi:10.1159/000346169 http://web.a.ebscohost.com.proxy.lib.uni.edu/ehost/detail/detail?vid=4&sid=54ef7457-53d4-4f27-b6e7-bd7942503869%40sessionmgr4003&hid=4104&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=psyh&AN=2013-22951-001 I will be honest, this one is where I got most of info. I enjoy using this database because it usually find my topic in an area that is somewhat related to psychology. Also its accreditation is great so I use it to find articles for research projects in other classes too. This particular article was a bit of a pain to read because they use a lot of scientific lingo in it, but that being said it had basically everything I needed for this assignment.
2) http://www.brightfocus.org/macular/about/risk.html This site I thought was great because it goes into detail about the different genes that can contribute to AMD, it also categorized the demographics of those that are more likely to get AMD
3) https://www.youtube.com/watch?v=NOAXlWJNbcE This is literally a 25 second video that shows a visual of dry AMD and I felt that helps people better understand the area I am talking about.
I think the topic of AMD is an interesting one, and I love how you connected this issue to your grandma. Nice job! For future assignments, try to go more in-depth about your topic. What else don't we know about AMD that the reader might find helpful. Cant wait to see what you come up with for your next blog post!
A subject of mystery since the beginning of time, the photic sneeze reflex is now widely recognized as a phenomenon affecting as many as 1 in 3 people. In recent years, several studies have cropped up regarding sneezing and its various causes. Medically, a sneeze is normally prompted by the detection of irritation within the nose. The sneeze is meant to remove whatever irritation may be present. In certain instances, studies have found a large number of odd causes related to sneezing. The most widespread of these is the photic reflex, sudden exposure to bright sunlight. Research does show there is a threshold for light contrast which elicits the sneeze response, only sudden extreme change in exposure to bright light seems to cause the reflex. Additionally, the latency effect shows that repeating instances of sudden exposure seem to prevent the phenomenon from reoccurring.
Leading theories attribute the reflex to mixed-up neural signals in the optic and trigeminal nerves or possibly branches of the parasympathetic nervous system. The optical-trigeminal summation theory is based on the proximity of these two nerves. In a normal sneeze, nasal congestion or irritation is detected, and a signal is transmitted to the brain via the trigeminal nerve, thereby prompting the motor sneeze response. Alternatively, the theory suggests sudden change in light energy, signals carried to the brain by the optic nerve, could switch over to the trigeminal nerve, causing the subsequent sneeze response.
At the moment, technology is not powerful enough to track the individual neurons responsible for the sneeze response, so specific experimental studies regarding the photic response are not currently in progress. We have determined there is a significant moderate correlation showing the reflex is hereditary, a dominant trait. This seems to be the case regardless of what the sneeze stimulus is – food, bright light, or the usual nasal irritation. Researchers also seem to agree that the cause is probably in the brain, based on its involuntary nature.
One study in particular found intravenous anesthetics, particularly propofol, may be implicated in the sneeze response. The same response was not observed in patients receiving local injection anesthesia. Further study might focus on the sedative effects on the nervous system with regard to sneezing.
Under normal conditions, the reflex itself is not harmful or dangerous, but possibly annoying. I’ve often wondered what could happen if a sneeze caught me by surprise while driving. Imagine if there was black ice - Scary! The genetic nature the reflex seems to possess suggests it is related to other neurological disorders, such as epilepsy or migraines. Similar to the optical-trigeminal summation theory of the photic sneeze reflex, they are thought to be caused by swapped signals between nerves. Studying any of these conditions might shed light on the other,
In any of the research on the sneeze reflex, one problem remains. As an involuntary response, it is difficult control in the experimental response. The study must be carefully designed to ensure the validity of results, being especially careful to avoid fake sneezes.
http://eds.b.ebscohost.com.proxy.lib.uni.edu/eds/detail/detail?vid=2&sid=2bcfeb73-383f-481d-8881-7b820a52fef7@sessionmgr115&hid=119&bdata=JnNpdGU9ZWRzLWxpdmU=#db=afh&AN=56550798
Explains leading optical-trigeminal summation and theory and parasympathetic generalization theory;
http://eds.b.ebscohost.com.proxy.lib.uni.edu/eds/detail/detail?vid=4&sid=2bcfeb73-383f-481d-8881-7b820a52fef7%40sessionmgr115&hid=103&bdata=JnNpdGU9ZWRzLWxpdmU%3d#db=edselp&AN=S0002939408001499
In depth study of injection/intravenous anesthetics on the sneezing reflex in the context of eye surgery. This study had a lot of background information regarding the sneeze response, and encourages medical professionals to be aware of the danger that may be present to patients undergoing surgery, exposed to anesthesia, and prone to damage as a result of sneezing while operating.
http://eds.a.ebscohost.com.proxy.lib.uni.edu/eds/detail/detail?vid=2&sid=7a1ac213-fcee-45f6-938e-7706268a229c@sessionmgr4002&hid=4203&bdata=JnNpdGU9ZWRzLWxpdmU=#db=afh&AN=38598016
This article contains details on the history of sneeze studies, including the photic reflex. It also explores the cause behind other seemingly unrelated causes of sneezes.
Terms Used: photic sneeze reflex, latency effect, light energy, neural signal, optic nerve, Optical-Trigeminal Summation Theory, Parasympathetic Generalization Theory, trigeminal nerve, parasympathetic nervous system, dominant trait,
1a) the topic I chose has to do with the “photic sneeze reflex.”
1b) this topic relates to the chapter because the chapter is about vision. Photic Sneeze Reflex is sneezing when exposed to a bright light.
1c) this topic gained my interest because it is a reflex the body produces but has yet to be understood by historys greatest minds and scholars. This and many other phenomenons our body demonstrates but yet are not understood interests I because our society doesn’t react well when we cannot figure something out.
My first source delivers a more descriptive description and overview of this condition. The photic sneeze reflex (also know as photoptarmosis, “sun sneezing”) is a condition of uncontrollable sneezing in response to numerous stimuli, such as looking at bright lights or periocular (surrounding the eyeball) injection. This condition goes on to affect 18-35% of the population, but the action demonstrated is not well understood. Aristotle and Bacon have gone about researching the reflex but there is no evidence on this action. Inheritance in an autosomal dominant fashion has been investigated, but yet the hereditary adoption of this reflex remains misunderstood. A study conducted at the University of Alabama at Birmingham School of Optometry, found that of photic sneezers, females represent 67%, and Caucasians represent 94%. A correlation between the presence of a deviated septum and photic sneezing, showing that possibly photic sneezing is more likely acquired than inherited. What’s the difference between photic sneezing and just a regular sneeze? Sneezing in general is caused by irritation in the nasal cavity, photic sneezing relates to the stimulus, which in some cases can be unusual.
My second source explains and delivers theories presented by scholars on the “photic sneeze reflex.” Eckhardt et al, in 1943 suggested that stimulating the optic nerve triggers the trigeminal nerve. The impulses are then transmitted to the optic nerve while other impulses are directed to another nerve. This impulse then delivers nasal stimulation to the nerves. Watson has the next theory; light falling on the retina stimulates fibers to the pretectal nuclei, which then sends interneurons to another nuclei. The tramission between these fibers from the cornea produce this sneeze.
My final source provides a lot of the same information obtained from my other sources but yet provides a theory that I can understand better and is easier to comprehend. Nicholas Lander, a professor at the University of Zurich, exposed participants to a bright light and measured their brain activity. By using a EEG, he described that the visual system in the brain can be a sensitive function, Overstimulation of light triggers a panicked response from other parts of the brain, including the somatosensory system which controls sneezing. He emphasized that a sneeze is triggered by irritation, but moisture has no influence. Nerves that control facial sensitivity and motor control senses this irritation, the optic nerve then sends visual information from the retina to the brain. This sudden burst of light could send a signal to restrict the pupil and be sensed by the trigeminal never and be mistaken by the brain as the nose being irritated, which in turn creates the sneeze.
In conclusion, whether the photic sneeze reflex is produced due to irritation, nasal stimulation, or misinterpretations of pathways of the brain. Studying and analyzing these neurological disorders may provide insight towards gaining meaning to migraines, epilepsy, and etc. Providing research and logical theories on why our body does something provides us with knowledgeable information that can be very beneficial possibly in the future. Now only if I knew, as a male, why my body shivers sometimes when urinating.
http://en.wikipedia.org/wiki/Photic_sneeze_reflex
I chose this website because it gave a more vivid description of the “Photic Sneeze Reflex” compared to the textbook. And the facts included were a plus!
http://www.medscape.com/viewarticle/714420_6
Using this website provided me with information and theories produced by scholars.
http://www.todayifoundout.com/index.php/2014/06/sun-sneeze/
This source provided me with a lot of the same information as the previous sources, but it also included an additional theory that didn’t include as many medical terms and was in turn easier for me to comprehend and understand.
Your assignment had great structure and you were able to nicely tie your sources together. You did a thorough job of going in-depth about the photic sneeze reflex. Great job!
I chose the topic of age-related macular degeneration (AMD), in the chapter readings we talked about eyes and how we process and see different items. More specifically the book talked about AMD and how this disease is associated with aging and how it happens over a period a length of time as we age and could eventually lead to complete blindness. Something that I have found very interesting overtime is how important our eyes can be and how it would not be very easy for me to accept total blindness. I have had to have glasses since I was little and looking more into how our eyes work and can deteriorate over time makes me want to learn more about AMD and different diseases that can happen within the eyes.
Age-related macular degeneration is when there is deterioration of the eye’s macula, this is just a small area within the retina. The macula is the part of your retina that is responsible for your vision which helps to fine tune a picture so that you are able to see it clearly. This is the area of the eye that helps you do things like thread a needle, read small print. Many people develop AMD as a natural part of their aging process. It is the leading cause of vision loss among people 50 years of age or older. Each case of AMD is different but this is something that could advance so slow that vision loss completely does not occur for a long time after being diagnosed, in others it could happen very fast and could cause blindness in just one or both eyes.
There are two main types of AMD there is the dry form and wet form. The “dry” form of macular degeneration is when drusen occurs (yellow deposits in the macula). However a small drusen may not cause changes in a persons vision but these drusens can grow in size and increase in number causing dimming or distortion of vision, most people find these when they are reading. Wet form is when the blood vessels grow abnormally from the choroid underneath the macula. The blood vessels leak blood and fluid into the retina causing distortion in the vision that will make straight lines look wavy. Most patients with AMD have the dry form of the disease and can lose some or all of their central vision although the dry form can lead to the wet form. Only about 10% of people with AMD develop the wet form they do make up the majority of those who experience serious vision loss from the disease.
There are many different risks factors involved with AMD, the disease is most likely to occur in older age. Research has shown that smoking doubles the risk of AMD and is more common in Caucasians than among African-Americans or Hispanics/Latino. AMD is also at a higher risk if there is a trace in the family history. Research has shown that you may be able to reduce your risk of AMD by avoiding smoking, exercising regularly, maintain normal blood pressure and by eating a healthy diet rich in green leafy vegetables and fish.
There are many different ways that AMD is detected but the early and intermediate stages of AMD start without symptoms. Some tests include visual acuity test, dilated eye exam, fluorescein angiography, and optical coherence tomography. The test that I found most interesting was the amsler grid, vision professionals can have you look at a amsler grid and tell by if your central vision causes changes in the lines on the grid making them wavy or even disappear as being a sign of AMD.
http://www.geteyesmart.org/eyesmart/diseases/age-related-macular-degeneration/- this web page had very detailed information and the pictures did a great job at visually explaining the meaning of AMD at a more clear level.
https://www.nei.nih.gov/health/maculardegen/armd_facts- This web page broke down and clearly explained some of the hidden facts about AMD that I didn’t see in any other Webpage that I looked at and helped me to better understand clearly.
http://www.webmd.com/eye-health/macular-degeneration/age-related-macular-degeneration-overview- this webpage was what I started with to look at the information about AMD from the “dumest” point of view so that I was better knowlagable about what the diease was and went from there to get a broader understanding.
Terms: AMD, Vision, Macula, retina, amsler grid, acuity test, fluorescein angiography, optical coherence tomograpgy, dry form amd, wet form amd.
Nice job at going in-depth about your topic! You explained the information in a clear and concise way. Overall, fantastic job.
I chose the topic of age-related macular degeneration (AMD) for further research. The book mentions this in some detail, but I wanted to see if I could find any information that went beyond its discussion. I find it interesting, because I honestly do not know how I would handle losing my eye sight and this is a relatively common condition for people as they age.
Macular degeneration can happen at any point in life, but age-related macular degeneration is much more common even though it only affects older adults (thus the age relation). The macula is a part of the retina that is responsible for the clarity of the center of our field of view. When the macula is damaged, one experiences a loss of vision in the center of the field of view. This leads to trouble discerning similar colors/contrasts, scotomas (missing areas of vision), and straight lines appearing curved (especially in an Amsler grid), among other symptoms. The Amsler grid is essentially just a grid of horizontal and vertical lines that form a grid of same shaped and sized squares. When one experiences AMD, the lines will appear curved despite them being physically straight.
There are two types of AMD: dry and wet. The dry form, also known as central geographic atrophy, is caused by the atrophy of the retinal pigmenet epithelial layer below the retina which causes vision loss through the loss of photoreceptors in the central part of the eye. The wet form, also known as choroidal neovascularization, is vision loss due to abnormal blood vessel growth in the choriocapillaris through the Bruch's membrane. The blood vessels enter the eye and begin spreading. However, these blood vessels are very fragile, and inevitably cause blood leakage into the eye around the macula. Between the bleeding and scarring caused by the intrusive blood vessels, irreversible damage is eventually done to the photoreceptors.
There is no medical or surgical treatment available for dry AMD, but there have been trials suggesting the possible benefits of some vitamin supplements with high doses of antioxidants. While this is no cure and cannot undue any damage to the eye, it may slow the advance of AMD or possibly help prevent it in the first place. While still not guaranteed, there is a better option for the treatment of wet AMD. Antiangiogenics can be injected into the eye to stop the spread of the new blood vessels in the eye and, in some cases, even cause regression of the vessels. Stopping the spread of the blood vessels will of course keep the vision from becoming any more impaired, but if the blood vessels actually begin to recede and not too much scarring has occurred, then the patient may actually regain some eyesight.
http://www.webmd.com/eye-health/macular-degeneration/age-related-macular-degeneration-overview - I chose this site because of it's combination of extensive facts and plain language that is clearly targeted to people who do not have much or any background in the topic.
https://www.youtube.com/watch?v=wj2WI7wjcMI - I used this source because visual demonstrations are always very helpful in helping me learn new material.
http://en.wikipedia.org/wiki/Macular_degeneration - I chose this source because Wikipedia almost always has some pretty good information presented in an easy to read fashion that is well organized. I made sure to cross-reference with the other sources for reliability.
Terms: Age-Related Macular Degeneration, Retina, Macula, Scotomas, Amsler Grid, Central Geographic Atrophy, Choriocapillaris, Bruch's Membrane, Photoreceptors, Choroidal Neovascularization
I loved how you nicely tied the sources together, and your paper was nicely structured. You did a wonderful job at going in-depth about your topic, so keep up the great work!
My topic was macular degeneration. This topic relates to the chapter because it is a disorder with a person’s vision. I am interested in macular degeneration because I have always been interested different disorders. Macular Degeneration is particularly interesting because before I did this research I knew little to nothing about it. I knew it led to decreased ability to see, but I didn’t know how or in what way.
Age-related macular degeneration (AMD) is a disorder in vision that causes central vision loss. It is caused by the damage and deterioration of the blood vessels in the macula. The macula is the central portion of the retina, and keeps vision detailed. AMD typically occurs in older individuals (60 or over). Those of who are of caucasian decent, have family history of AMD, and smoke are also at higher risk for this disease.
There are two types of AMD. The first type is dry AMD (atrophic). Dry AMD occurs when the blood vessels beneath the macula thin out and weaken. Then, deposits of yellow drusen are made. This usually is the starting point for all with AMD. This is the less severe type, and there is limited central vision loss. The other, more severe, type of AMD is wet (exudative). This is caused when new abnormal vessels form to replace the old ones. Since they are not quite right, they leak bodily fluids. It can cause great life impact and take away the abilities to read, drive, and recognize people from far away. Thankfully, wet AMD is less common, occurring in 10-15% of patients.
There is no cure at the moment for AMD. There is a treatment called the AREDS formula, which contains several vitamins and minerals that may slow the deterioration of the macula. However, any damage done cannot be reversed.
http://www.nlm.nih.gov/medlineplus/ency/article/001000.htm
https://www.macular.org/what-macular-degeneration
https://www.nei.nih.gov/health/maculardegen/armd_facts
I think you do a nice job at connecting your sources to one another and you explained your topic in a very understandable way, so good job! For future assignments, please try to go more in-depth about your topic when you're drawing from your sources. May be try to find more substantial sources so you have more to talk about it. Can't wait to see what you come up with for your next blog!
My topic was macular degeneration. This topic relates to the chapter because it is a disorder with a person’s vision. The chapter when into detail about the basics of how the eye is able to see. When these parts are compromised, disorders can occur. This is how macular degeneration occurs. I am interested in macular degeneration because I have always been interested different disorders of the human body. I find that things that don’t work quite right help me to understand how things work when they are functioning properly.4 Macular Degeneration is particularly interesting because before I did this research I knew little to nothing about it. I knew it led to decreased ability to see, but I didn’t know how or in what way.
Age-related macular degeneration (AMD) is a disorder in vision that causes central vision loss. A person with this disorder would have a central portion of their field of vision blurred severely to the point they have a spot which is essentially blind. AMD is caused by the damage and deterioration of the blood vessels in the macula of the eye. The macula is the central portion of the retina. The primary purpose of the macula is to keep vision detailed. AMD typically occurs in individuals of an older age, mostly those 60 years or older. The risk for this disorder increases for those of who are of Caucasian decent, those who have family history of AMD, those who are women, those who consume high-fat diets and those who smoke.
There are two types of AMD. The first type is called dry AMD or atrophic AMD. Very common in older adults, Dry AMD occurs when the blood vessels beneath the macula begin to thin out and weaken. After the blood vessels thin out, deposits of yellow drusen are made. Yellow drusen is a build up of extracellular matter. The Dry kind of AMD is usually is the starting point for all people who develop AMD. This is the less severe type. With Dry AMD, there is usually very limited central vision loss. Common symptoms of this type include objects in the center field of vision appearing dim or blurred, along with faded color vision. There may also be some trouble reading small print or small details. Despite this, those with Dry AMD are typically able to carry on with normal everyday tasks well enough. This is at least until later stages of the disease. Later on, a blurred spot may occur in central vision that increases in size as time goes on. Faces of others may become harder and harder to recognize as well. There is also another, more severe, type of AMD which is called Wet AMD, or exudative AMD. This type of the disorder is caused when new abnormal vessels are formed in order to replace the older weakened ones. Since they are not formed quite correctly, they may leak bodily fluids. This leakage can then cause great life impact by taking away important abilities such as the ability to read, drive, and recognize people from far distances. Most of the time, the earliest symptom of Wet AMD is that straight lines appear to wavy. In the Wet form of AMD, the portion of decreased vision in the central vision field is actually dark instead of just blurry. Thankfully, Wet AMD is far less common than Dry AMD, occurring in 10-15% of all patients with AMD.
In order to diagnose AMD, one must attend an eye appointment. At this appointment, special eye drops will be used to dilate the pupils. This allows the ophthalmologist to look for any changes occurring in the macula along with traces of yellow drusen. There is also a test done using an Amsler Grid. If a patient views the lines on this grid as wavy instead of the straight lines they are, AMD could be present. There is no cure at the moment for AMD. There is however, a treatment called the AREDS formula. This formula contains several vitamins and minerals that may slow the deterioration of the macula. This slows the progression of the disease. Yet, any damage, which has already been done, cannot be reversed with current medical technology.
http://www.nlm.nih.gov/medlineplus/ency/article/001000.htm
I used this site because it was a baseline article describing the basics of the disease. It provided simple, good information that allowed me to have a basic understanding before diving deeper into the mechanics of the disorder.
https://www.macular.org/what-macular-degeneration
I used this site because it was an organization site for a foundation that supports AMD. I thought this fact would provide good prospective on the disorder from the point of view of those most involved with its effects.
https://www.nei.nih.gov/health/maculardegen/armd_facts
I chose this article simply because it had a lot of good information on the subject. It allowed me to learn a lot of detailed facts that were not included in the baseline article.
Terms: Vision; Macular Degeneration; macula; retina; blood vessel; drusen; Wet AMD; Dry AMD; central vision loss; pupils; Amsler Grid; AREDS formula; vitamins; minerals; deterioration
the topic I am interested in is the one on illusions. the mach bands part of the book. this topic relates to the chapter because it goes back to how the eye works and how complicated it is. there are so many different parts to the eye and it can play tricks on you. I have always found illusions interesting. there are certain little tings that effect the way the eye see things. different lights and shades of color change the way we see things. a picture may look like its moving when its not. one color looks darker then the other when they are exactly the same. the book and other websites talk about how seeing is not always believing. i cant help but relate this to eye whiteness testimonies. when there is specific lighting the way we see the area and what is really there.
this website shows different examples of illusions I like this cite because of how it truly shows what are eyes are able to see. http://www.wikiradiography.net/page/Mach+bands+and+other+Optical+Illusions
the second website I liked becasue it gave a overview of what mach bonds are.
http://en.wikipedia.org/wiki/Talk%3AMach_bands
the thrid has a whole lot of information where i got most of what i have learned
http://www.skidmore.edu/~hfoley/Perc4.htm
I think you picked a great topic, and I think you gave some great examples, but next time, try to go more in-depth on the topic. If your sources aren't giving you a lot of information, then try searching for others...that way you can go into more detail. Can't wait to see what you come up with next time!
1a) State what your topic is.
I choose to do my discussion and further research over RODS and CONES.
1b) Discuss how the topic relates to the chapter.
The topic of rods and cones within our eyes relates to this chapter because it explains how the visual field works, how certain information or sighting are processed into our brain to operate that part of the brain properly. It explains how we see things in the way that we do; how they are perceived the way that they are.
1c) Discuss why you are interested in it.
I find this interesting because being red/green color blind runs in my family and the rods and cones help us see light and color, also they help us see the shape to understand what we are seeing so I would like to find more information on this topic to be more knowledgeable on the subject.
Basically beginning my research I discovered the rods and cones are both types of photoreceptors and they are the only two photoreceptors in the human eye.
The rods are responsible for vision at low light levels, they do not control color vision, and they also have a low spatial acuity.
Cones are active at higher light levels, they are capable of color vision and are responsible for high spatial acuity. The central fovea is populated exclusively by cones. There are 3 types of cones which are called short-wavelength sensitive cones, the middle-wavelength sensitive cones and the long-wavelength sensitive cones. The cones would be what are responsible for people not being able to see certain colors (colorblind).
There are about 120 million rods in the human eye and only 6 to 7 million cones. The rods are much more sensitive than the cones. The cones can be divided into red cones, green cones and a small amount of blue cones. The blue cones are identified by their sensitivity and small amount of light they see. They are unique among the cones because they constitute only about 2 percent of the total number and are found outside the central fovea where the green and red cones are largely located.
Overall my goal was to learn about color blindness and see how much the rods and cones actually have to do with it. What I found is that color blindness is usually inherited, it happens when one of the cone receptors (red, green or blue) seem to be missing or don't work right. You can also see the colors in a different shade than others do make you be "color blind specific" to certain colors. This form of color blindness is more common in men and it is something you are born with it doesn't occur over time.
However, A color vision problem isn't always inherited. In some cases a person can develop a color vision problem which can be caused by many things; aging, eye injury, side effects to medicine and many more.
Terms: rods, cones, photoreceptors, wavelengths, receptors, colorblind, spatial acuity, central fovea, red, blue and green cones.
http://www.cis.rit.edu/people/faculty/montag/vandplite/pages/chap_9/ch9p1.html
This website gave me great definitions of rods and cones and explained to me what to further research.
http://hyperphysics.phy-astr.gsu.edu/hbase/vision/rodcone.html
This website thought me of the specific types of cones, red, green and blue and gave me much detail about the blue cones which were something I had never heard of.
http://www.webmd.com/eye-health/tc/color-blindness-topic-overview
This was my favorite website it told me the details of colorblindness, why it happens, how it happens and the mechanics of how it happens. It was extremely useful.
Nice job at explaining your topic in an understandable way. I like that your paper also had nice structure. Keep up the great work!
Cataracts
Cataracts were discussed briefly in the chapter and I was interested in the subject because i remember watching a documentary on a doctor in India (or I think it was India) that would do procedures on elderly people with cataracts for free and I wanted to learn more.
The lens of the eye consists of densely pack proteins called crystallins. As we age, these proteins break down and form irregularities in the lense. This makes the lense cloudy and these irregularities scatter and refract the light. This will start to happen to everybody around age 45 but for most people it will not be to a degree that will impair your vision too much. But by age 75 most people will have cataracts that affect their vision. Although for some unfortunate people cataracts will impact your sight. Some conditions that speed up the formation of cataracts include eye injury, eye inflammation, diabetes, radiation exposure, smoking and overexposure to sunlight. Preventing cataracts is as simple as not smoking and wearing sunglasses on sunny days. Standard eye exams and slit-lamp examinations are used to diagnose cataracts. The slit-lamp examination is a low powered microscope combined with a high intensity light beam that can be adjusted to a very thin beam. The doctor used this instrument to look at your eye and may use a yellow dye to see things in more detail. The treatment of cataracts varies by intensity and age. For early formations of cataracts the treatment is as simple as changing your eyeglass prescription and using better lighting. The only treatment for cataracts is to surgically remove it and replace the lens with a synthesized one. This is only recommended when the cataracts impair your vision so much that you cannot drive or read or complete daily activities. There are two main types of surgery for cataracts but in most procedures an intraocular lens is inserted to replace the old cataract lens. This lens is either made of silicone or acrylic material, these lenses are foldable in order to insert them through the opening made in the cornea and through the iris. These lenses have been becoming more popular since the 1960s but was not approved by the FDA until 1981. Before the invention of the intraocular lense, patients would have their lens removed and have to wear extremely thick eyeglasses or a special type of contact lens. These lenses can also be used to treat astigmatism and presbyopia.
Sources: http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001996/#adam_001001.disease.causes
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0004331/
http://en.wikipedia.org/wiki/Cataract_surgery
Terms: crystallins, scatter, refract, intraocular lens, cornea, iris, astigmatism, presbyopia
Nice job at explaining your topic in an understandable and thorough way. Overall, nice job!
Topic: Age-related Macular Degeneration (AMD).
This topic comes directly from Chapter 2. AMD is a common eye condition and a leading cause of vision loss among people age 50 and older. It causes damage to the macula (pg. 42), defined as “the central part of the retina that has a high concentration of cones.” Also described as that small spot near the center of the retina and the part of the eye needed for sharp, central vision, which lets us see objects that are straight ahead of us.
Because AMD has to do with the macula in an eye which is made up of millions of light-sensing cells that provide sharp, central vision and it is the most sensitive part of the retina which is at the back of the eye. And because we know that the retina’s goal is to turn light into electrical signals and send them to the brain we know that if and when the macula is damaged, the center of your field of view may appear blurry, distorted, or dark. This is because the the fovea has been affected as well, another aspect of the macular. All of this directly linked to the chapter and clearly with the retina being one of the main parts of the eye it is a great topic to research and find out more about.
One of the main reasons I found and still find this topic so interesting is because I know two people who suffer from this particular disease. The first person is my mother and another was my grandmother (who died before going blind). According to these people they have described seeing peoples faces, watching television and reading a book or magazine as some of the most difficult things to do or see when AMD is severe. This is not only difficult to hear but frightening as I wonder if I currently have the disease and not even know.
According to research I did, the early onset and intermediate stages of AMD usually start without symptoms. So when it comes to detection, It’s almost impossible to find unless you actually looking for it or other things within the eye. Only a comprehensive dilated eye exam can detect AMD. Here are the latest ways/exams that one must have done in order to identify AMD:
Visual acuity test. This eye chart measures how well you see at distances.
Dilated eye exam. Your eye care professional places drops in your eyes to widen or dilate the pupils. This provides a better view of the back of your eye. Using a special magnifying lens, he or she then looks at your retina and optic nerve for signs of AMD and other eye problems.
Amsler grid. Your eye care professional also may ask you to look at an Amsler grid. Changes in your central vision may cause the lines in the grid to disappear or appear wavy, a sign of AMD.
Fluorescein angiogram. In this test, which is performed by an ophthalmologist, a fluorescent dye is injected into your arm. Pictures are taken as the dye passes through the blood vessels in your eye. This makes it possible to see leaking blood vessels, which occur in a severe, rapidly progressive type of AMD.
Optical coherence tomography. This is something very similar to an ultrasound, which uses sound waves to capture images of living tissues. OCT is similar except that it uses light waves, and can achieve very high-resolution images of any tissues that can be penetrated by light—such as the eyes. After your eyes are dilated, you’ll be asked to place your head on a chin rest and hold still for several seconds while the images are obtained. The light beam is painless. (During the exam, your eye care professional will look for drusen, which are yellow deposits beneath the retina. Most people develop some very small drusen as a normal part of aging. The presence of medium-to-large drusen may indicate that you have AMD.)
Other risk factors for AMD include: Smoking (research shows that smoking doubles the risk of AMD.), Race (AMD is more common among Caucasians than among African-Americans or Hispanics/Latinos), Family history (people with a family history of AMD are at higher risk). Researchers have also found links between AMD and our own lifestyle choices, i.e. smoking. You might be able to reduce your risk of AMD or slow its progression by making these healthy choices like exercising regularly, maintaining normal blood pressure and cholesterol levels and by eating a healthy diet rich in green, leafy vegetables and fish.
The different treatments for AMD that I discovered after some some research are as follows:
The most recent discovery/treatment was discovered by VisionCare Ophthalmic Technologies in June 2012, and it is an implantable miniature telescope that magnifies the overall image while reducing the relative size of the central blind spot caused by macular degeneration. It’s about the size of a pea and it is just for certain people who experience severe vision loss caused by advanced ("end-stage") of macular degeneration. Another option is Lucentis, approved by the FDA (June 2006) for treating the more advanced or "wet" form of macular degeneration. Lucentis (ranibizumab) is a form of the colorectal cancer treatment drug, Avastin. Lucentis works by inhibiting proteins called vascular endothelial growth factor (VEGF), which stimulate the growth of new blood vessels in the body. VEGF is thought to contribute to development of macular degeneration by promoting the growth of abnormal blood vessels in the retina.
Currently, there is no cure for AMD.
http://www.allaboutvision.com/conditions/amd-treatments.htm
http://www.amd.org/
http://www.artificialretina.energy.gov/
Terminology: Aged Macular Degeneration (AMD), wet AMD, dry AMD, disease, eye, macula, light-sensing cells, fovea, research, retina, vision, proteins, Lucentis, abnormal, treatment, colorectal cancer, drug, Avastin, vascular endothelial growth, factor, stimulate, blood vessels, cure, blood pressure, light, dilate, exam, healthy, implantable miniature telescope, blind spot, drug, development, ophthalmic, Amsler grid, drusen, Fluorescein angiogram.
Great job at going in-depth about AMD. You do a wonderful job at connecting the sources to one another. WONDERFUL job! Keep up the great work.
I chose to search age related macular degeneration, this is one of the topics covered in the chapter that I was interested in learning more about. I thought it sounded interesting because it's something I have never heard of before that could affect anyone.
Macular degeneration is a hereditary disease that has an onsite after the age of 60. It happens in the macula which is a needle sized area in the retina. There are two types, Dry and wet. Dry happens when little yellow dots, called Drusen appear under the retina. Wet happens when abnormal blood vessels grow over your retina. Dry is the most common being 90% of all cases, but wet also does happen. Something I found very interesting about this disease is the risk factors. There are the hereditary risks, but also being overweight, smoking, being female and light skinned. Most interestingly it can really depend on the color of your eyes. Lighter colored eyes, blue, green, hazel, are at a much higher risk than darker toned eyes. More times than not, it does not cause complete blindness, but blind spots occur generally in the center of your site line. They are currently working on different treatments for this, they have lucentis, a drug that will slow down the process. Recently they have been working on a tiny telescope to surgically put in the eye in order to receive full vision which is absolutely amazing that they are able to do that surgery.
http://www.allaboutvision.com/conditions/amd-treatments.htm
http://www.webmd.com/eye-health/macular-degeneration/age-related-macular-degeneration-overview?page=2
http://www.geteyesmart.org/eyesmart/diseases/age-related-macular-degeneration/
Age related macular degeneration, Drusen, Retina, Mucula, Lucentis,
Sensation & Perception
Topical Blog 3 – Photic Sneeze Reflex
1/28/2015
A subject of mystery since the beginning of time, the photic sneeze reflex is now widely recognized as a phenomenon affecting as many as 1 in 3 people. In recent years, several studies have cropped up regarding sneezing and its various causes. Medically, a sneeze is normally prompted by the detection of irritation within the nose. The sneeze is meant to remove whatever irritation may be present. In certain instances, studies have found a large number of odd causes related to sneezing. The most widespread of these is the photic reflex, sudden exposure to bright sunlight. Research does show there is a threshold for light contrast which elicits the sneeze response, only sudden extreme change in exposure to bright light seems to cause the reflex. Additionally, the latency effect shows that repeating instances of sudden exposure seem to prevent the phenomenon from reoccurring.
Leading theories attribute the reflex to mixed-up neural signals in the optic and trigeminal nerves or possibly branches of the parasympathetic nervous system. The optical-trigeminal summation theory is based on the proximity of these two nerves. In a normal sneeze, nasal congestion or irritation is detected, and a signal is transmitted to the brain via the trigeminal nerve, thereby prompting the motor sneeze response. Alternatively, the theory suggests sudden change in light energy, signals carried to the brain by the optic nerve, could switch over to the trigeminal nerve, causing the subsequent sneeze response.
At the moment, technology is not powerful enough to track the individual neurons responsible for the sneeze response, so specific experimental studies regarding the photic response are not currently in progress. We have determined there is a significant moderate correlation showing the reflex is hereditary, a dominant trait. This seems to be the case regardless of what the sneeze stimulus is – food, bright light, or the usual nasal irritation. Researchers also seem to agree that the cause is probably in the brain, based on its involuntary nature.
One study in particular found intravenous anesthetics, particularly propofol, may be implicated in the sneeze response. The same response was not observed in patients receiving local injection anesthesia. Further study might focus on the sedative effects on the nervous system with regard to sneezing.
Under normal conditions, the reflex itself is not harmful or dangerous, but possibly annoying. I’ve often wondered what could happen if a sneeze caught me by surprise while driving. Imagine if there was black ice - Scary! The genetic nature the reflex seems to possess suggests it is related to other neurological disorders, such as epilepsy or migraines. Similar to the optical-trigeminal summation theory of the photic sneeze reflex, they are thought to be caused by swapped signals between nerves. Studying any of these conditions might shed light on the other,
In any of the research on the sneeze reflex, one problem remains. As an involuntary response, it is difficult control in the experimental response. The study must be carefully designed to ensure the validity of results, being especially careful to avoid fake sneezes.
http://eds.b.ebscohost.com.proxy.lib.uni.edu/eds/detail/detail?vid=2&sid=2bcfeb73-383f-481d-8881-7b820a52fef7@sessionmgr115&hid=119&bdata=JnNpdGU9ZWRzLWxpdmU=#db=afh&AN=56550798
Explains leading optical-trigeminal summation and theory and parasympathetic generalization theory;
http://eds.b.ebscohost.com.proxy.lib.uni.edu/eds/detail/detail?vid=4&sid=2bcfeb73-383f-481d-8881-7b820a52fef7%40sessionmgr115&hid=103&bdata=JnNpdGU9ZWRzLWxpdmU%3d#db=edselp&AN=S0002939408001499
In depth study of injection/intravenous anesthetics on the sneezing reflex in the context of eye surgery. This study had a lot of background information regarding the sneeze response, and encourages medical professionals to be aware of the danger that may be present to patients undergoing surgery, exposed to anesthesia, and prone to damage as a result of sneezing while operating.
http://eds.a.ebscohost.com.proxy.lib.uni.edu/eds/detail/detail?vid=2&sid=7a1ac213-fcee-45f6-938e-7706268a229c@sessionmgr4002&hid=4203&bdata=JnNpdGU9ZWRzLWxpdmU=#db=afh&AN=38598016
This article contains details on the history of sneeze studies, including the photic reflex. It also explores the cause behind other seemingly unrelated causes of sneezes.
Terms Used: photic sneeze reflex, latency effect, light energy, neural signal, optic nerve, Optical-Trigeminal Summation Theory, Parasympathetic Generalization Theory, trigeminal nerve, parasympathetic nervous system, dominant trait,
I decided to further explore human night vision. It relates to Chapter two because chapter two covers the basis of the eye. I would like to research why humans have such terrible night vision compared to other animals because it is interesting as I know humans, at least at a long time ago need to be able to see in the dark just as much as most other animals yet we have night vision that is less than stellar.
2. While the human eye is impressive in many aspects, one aspect it falls short in is night vision. The two aspects of human vision that is limited are spectral range and intensity range. Spectral range is the portion of light that can be perceived, or seen. When it comes to human eyes, visible light is the only wavelengths that can be seen. They have a range of 380-750 nm. Infrared radiation is an example of a wavelength that plays a huge role in night vision. Many animals that are able to see in the dark due to having great night vision can see the infrared radiation wavelength. But humans cannot as it falls to low below the absolute threshold of human vision. The intensity of the photons that humans eye can perceive are .10. Some nocturnal animals can see as well as to perceive a single proton.
Rods play a huge role in night vision, because they are the part of the eye that does most of the work in night vision. Myopic vision is an example of the rod working with the cone during transitional periods. Dusk and twilight are the times during the day where the light is low enough that both the rods and cons are most effective if they work at the same time. Rods are very important because the rods are responsible, but not solely, for an animal’s ability to see at night because they impact the ability of the human to use contrast discrimination and Visual acuity. Visual acuity is “a measure of the finest detail that can be resolved by the eyes”. Contrast discrimination is the term for when the visual acuity is reduced at night. This happens because the decrease in light causes the eye to be able to detect less than during the day. Some factors like: glare, night myopia, and depth perception are severely impacted by low light. Glare reflected from windshield is worse in low light. Night myopia (aka night blindness) is a result of the light being too low for the rods to be able to function. Depth perception is hindered when the light is too low for the rods to function fully.
All of this knowledge has lead scientist to try to improve human’s night vision. Dark adaptation is an automatic process where each eye adjusts to a high light setting to a lowlight setting. We still don’t know how this works exactly, but do know that it involves biochemical, physical, and neural processes. Light adaption is the opposite of dark adaption because it uses cones, as opposed to rods. It takes 30-40 minutes from the rods to fully adapt to darkness while it only takes 5-7 minutes for the cones to fully adapt to bright light. Dark adaption is not the only way to improve human night vision.
Rental implants is an idea that is currently being played with as they have shown the possibly of returning sight to the blind. These implants are modified contact lenses that use an electric circuit and red light-emitting diodes that help the blind see because sight is and electrochemical signal that can be replaced with a working one. These implants could be altered slightly to increases the number of rods that are active which would improve night vision as we would be able to see more of the light spectrum than humans can without implants.
There are also some non-invasive ways to improve night vision. Using specialized goggles is one way for a person to improve their night vision. Pilots who fly at night were red goggles (which block all but the red light) to improve their night vision. Another way is image intensification, which relies on increasing the number of photons from various light sources (starlight and moonlight). An example of this is night vision goggles. Active illumination uses image intensification and near infrared light wave lengths to add light to the image so it can be seen with the naked eye. Thermal vision uses differences in temperatures of objects in the background and foreground to see in the dark, snakes are an example of an animal that uses this infrared vision to see.
3. terms:nm, Infrared radiation, wavelengths , light, visible, seen, perceived, vision
spectral range , intensity range, night vision, photons, absolute threshold , nocturnal animals Rods , Myopic vision , transitional periods, Dusk, twilight , contrast discrimination, Visual acuity, glare, night myopia, and depth perception , decrease in light , Dark adaptation, biochemical, physical, and neural processes, Light adaption , Rental implants , red light-emitting diodes , electric circuit ,light spectrum, red goggles , block , red light, image intensification, light sources ,starlight, moonlight, night vision goggles, Active illumination ,near infrared light wave lengths. Thermal vision uses differences in temperatures , background and foreground, infrared vision.
http://dujs.dartmouth.edu/winter-2010/the-quest-for-superhuman-vision-augmenting-our-most-valuable-sense#.VQmjj_nF9IE I picked this site because it clearly explained some physical limitations that lead to bad night vision in humans. I used it for: spectral range, intensity range, and Retinal implants.
http://www.aoa.org/optometrists/tools-and-resources/clinical-care-publications/aviation-vision/the-eye-and-night-vision?sso=y I picked this site because it clearly explained how the eyes work at night. I used it for: the bit on rods, metopic vision, visual acuity, glare, night myopia, depth perception, dark and light adaption, pilot use of specialized red glasses
Textbook. I used it for the definition of visual acuity.
http://rev.sagepub.com/content/7/1/238.abstract I picked this site because it is the abstract of an article that said the specialized goggles can help with night vision on military missions. I use it for the part on night vision goggles.
http://en.wikipedia.org/wiki/Night_vision I picked this site because it simply explained night vision. I used it for: image intensification, active illumination, and thermal vision