Category Archives: Vision

Reading Equals Needing Glasses

As a child for some reason I had always wanted glasses; I thought they were cool and wanted my own pair. But at the same time I thought I would have 20/20 vision forever as it seemed that only my brother’s and my dad had bad enough eyesights that warranted them needing glasses. I thought that I had inherited my mother’s eyesight and that since I was a girl I would not end up needing glasses as it seemed that needing glasses ran only on the male side of my family. But I was wrong.

When I was in the 8th grade I began noticing problems with my vision, but I didn’t pay too much attention to it as it was not really affecting me. But by the end of that year it became a very big problem! I could not see a thing any of my teachers wrote on the board or put on the overhead clearly even when I sat in the front row of the class. I was no more that 5 feet away from the board and even while squinting I still could not make out what was written very well. Turns out I had inherited my dad’s bad eyesight instead and was in serious need of glasses.

So that summer I ended up getting glasses. I was like a whole new world once everything was in focus and crystal clear. I found out that my not being able to see objects clearly far away, but being able to see objects up close clearly was called nearsightedness. But that was as far as I knew about the issue. I figured that since my eyesight started getting blurry around the time that I started to play handheld video games that was the cause; but as I learned in this class correlation does NOT equal causation.

Turns out that my problem of nearsightedness came from my love for books which I had inherited from my mom. What happens with nearsightedness is that the eye is a little longer that the normal shape it should be, so by the time the image passes through the lens (the part of the eye involved with this issue) and reaches the retina the that image is out of focus. So by getting glasses my problem was fixed as adding a lens on top of the lens of the eye allowed for the image to be pushed back a bit so when it did pass through my lens and reach my retina everything would be in focus.

So though my love for books is the cause for my needing glasses, I’m not too upset. I’m still able to read and I got my wish of being able to wear glasses (I guess I jinxed myself as a child). If it wasn’t for this class I would not have found out the cause of my eye problem and would not have gained a deeper appreciation for the eye and vision.

Monocular Cues

Back in the day, I was an aspiring artist; I tried my best to be better than everyone else, because what middle school student doesn’t want to be the best? Every single time I took my newest drawing to the art teacher though, she’d tell me that my work was flat and had no dimension, nothing popped out. She’d always try and show me how if I drew the duck, or mailbox really big in the front it would be like it was closer, and the smaller things were in the background, that would mean they were farther away. I never quite grasped the concept but instead of asking questions I’d just smile and move on and grumble about how she didn’t know what art was. All of the techniques she was trying to show me though, I now recognize as Monocular cues, which consist of cues for perceiving depth in the world. Drawing the duck larger than the things in the background? Well that was going along with relative size! I remember for one art project we had to draw skyscrapers. And myself, thinking I was just as good as Leonardo DaVinci or Rembrandt, drew a large rectangle on the paper. My art teacher, Mrs. Clark, almost immediately took it to the front of the class and explained that’s exactly what NOT to do. (My little middle school heart was broken that day). She explained that the taller the building got, the more we should taper it in so it looks like we’re looking up at the top of the building. And know, with all of my knowledge, I recognize she was utilizing linear perspective so that our pictures would look like the top of the building was really far away. She taught us many other art techniques, none of which really caught on with me. But now that I am versed in monocular cues I can appreciate the good artistic abilities she was trying to impart on us students, regardless of the fact that I still haven’t been able to draw them all too well.

The Trichromatic Theory and Color Blindness

The Trichromatic Theory is the idea that there are three receptors in the retina of the eye that are each sensitive to their own specific color. These three colors are red, green, and blue. Each of these color-sensitive cone cells has different sensitivities, with blue cones being the most sensitive and red cones being the least. The combination of these three colors can form any visible color in the color spectrum.

If one of the three basic color mechanisms is absent or not functioning, it is called dichromacy. This is a mild form of colorblindness which predominantly affects males. This is because the mutated gene that determines colorblindness is found on the X chromosome. Being that males only have one X chromosome, if they have a mutant X chromosome, they will express the trait for colorblindness. Since females have two X chromosomes, they will not express the mutation if they have a normal and a mutated chromosome; this is because the normal X chromosome will be able to override the mutant X chromosome. Men do not have the additional X chromosome to override any mutations they may have on their one and only X chromosome.

This topic is particularly interesting to me because my best friend’s father has colorblindness. Her father wanted to be a pilot ever since he was a child, but was ineligible because of his inability to distinguish different colors. One day while her father was interviewing for the position as a helicopter pilot, he realized that his red/green colorblindness would prohibit him from obtaining his helicopter license. The reason he was not able to get his pilot’s license is because color distinction is extremely crucial when it comes to dash instruments and gun signaling on the tarmac. There are some circumstances when pilots are issued a license with restrictions. An example of such a restriction would be prohibiting flying at night. In all, colorblindness is mild vision problem that can greatly impact your daily life, but typically does not cause extreme complications or problems if you catch it early.

Works Cited

Board, A.D.A.M. Editorial. “Color Blindness.” Color Blindness. U.S. National Library of Medicine, 06 Jan. 2011. Web. 06 Mar. 2014.

“Color Blindness: Causes, Symptoms, Diagnosis, and Treatment.” WebMD. WebMD, 14 Apr. 2011. Web. 03 Mar. 2014.