I spy with my little eye….

How many people can remember their mom telling them not to read in the dark?  Probably many.With all this new technology, there are many new problems to consider. Nintendo recently gave the warning that children under the age of six shouldn’t use the new 3D feature of their 3DS and computer vision syndrome is becoming much more popular.

The warning from Nintendo has raised a lot of questions about the effects of 3D technology on eyes and in particular developing eyes.  The concern Nintendo has is that before age six, it is believed that eyes are in a critical period of development.  Experiments have shown that if a young child cannot see out of one eye after a few years they will not be able to see out of the eye even if the problem is fixed. On the other hand if the same thing happened in an adult, when the problem causing the blindness in one eye is fixed they will be able to see normally again. This is because of how the brain processes the visual information.  The two eyes see slightly different images and then process the information into essentially a column of cells.  When both eyes work, the columns should alternate which eye the information came from by cell. But when only one eye works or is heavily favored then the columns only have information from that eye.  When vision is returned to the eye, the brain doesn’t know how to make the columns start alternating if they haven’t done it before.  It is more than just blindness that can cause one eye to become dominant over another though.  If the two eyes are misaligned or if they focus at different distances, then one eye will generally become dominant to prevent double vision.

In order to begin research on the effects of watching 3D on young eyes, Dr. Tychsen did research on baby Rhesus monkeys. While not a guaranteed indication that the effects observed will carry over to humans, it is very likely that the effects will be similar.  In Dr. Tychsen’s research, he had monkey’s watch 3D films throughout each day for three months.  The monkeys who watched the films had no difference in their visual development compared to those who did not watch the films. In fact, some researchers believe that the only potential concerns for have more to do with how much information the brain has to process and the fatigue that comes from that.

Surprisingly, it turns out that the 3DS may actually have visual benefits in the sense that it could have doctors diagnose issues that may result in learning difficulties in children at an earlier age.  Many vision problems can be treated much easier if they are detected early. The 3DS is essentially showing each eye a slightly different image, so when they combine you get the 3D effect.  Therefore, if one eye is dominant over another, there will be issues when viewing the 3D content as the information will not combine correctly and will not give the correct 3D effect.  When using the 3DS there are 3 signs that you need to get a comprehensive eye exam by an ophthalmologist because there may be an issue.  They are dizziness, discomfort, or lack of depth.

So what about computer vision syndrome?  We’ve all had those days where we’ve stared at the computer for way too long and before we know it, we’re rubbing our eyes, can’t focus and that nagging headache is building up, but why does it happen? Part of it is because of how the computer screen works.  When you stare at an unchanging object, the computer screen is not actually unchanging.  The screen is actually constantly refreshing itself and forcing you to refocus your eyes every time it refreshes.  Another cause is an underlying vision problem that is aggravated by the computer. And as you age, your eyes are changing anyways. So watch out baby boomers…computer vision syndrome is coming with carpal tunnel syndrome for those of you who are on the computer all day.

Proper work place set up.

So what can you do to prevent it? Well you have some options.  The easiest thing is to blink and take breaks more often.  If you blink more frequently as you work, it will help prevent dry eye and breaks will give your eyes time to refocus.  Also make sure you work station is set up properly. The diagram to the right shows the recommendations of the American Optometric Association.  You want the screen below your eyes and just over two feet away from your eyes.  Finally, do your best to reduce the glare on the screen either by changes in lighting or by adding an anti-glare screen.

For more information on these topics, here are some good articles:

  1. http://www.hhmi.org/senses/b410.html
  2. http://www.aoa.org/x17309.xml
  3. http://bits.blogs.nytimes.com/2011/01/05/eye-specialists-question-nintendos-warning-on-3-d-technology-and-children/
  4. http://www.aoa.org/x5253.xml
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This entry was posted in Science of Everyday Things by cbaker0313. Bookmark the permalink.

About cbaker0313

I am a senior at DePauw University majoring in computer science and math. Originally from Cedar Rapids, IA I stumbled upon DePauw by chance and fell in love on my visit. I haven't looked back since. Upon my graduation in May, I intend to pursue my Ph.D. in computer science. On campus I am actively involved as head tutor for computer science, chair of Women in Computer Science, captain of the swim team and president of Delta Gamma. As an active participant in Delta Gamma, I am interested in the effects of technology on vision as vision is the heart of the Delta Gamma Foundation.

4 thoughts on “I spy with my little eye….

  1. I found this blog really interesting! I have thought a lot about 3D and how exactly it works on your brain because I really didn’t have any exposure to it until about a year ago. Several friends have told me that it causes them to have severe headaches and nausea and that could possibly be because of the double image effect that is tricking your mind into seeing a 2D screen as a 3D (real 3D). I searched for a couple of articles and I found this very enthusiastic article that warns against the 3D in home entertainment:
    http://www.audioholics.com/news/editorials/warning-3d-video-hazardous-to-your-health
    Now I do realize that this is not extremely backed up with evidence because of the few primary articles that it mentions, but it definitely was an interesting read. It talks about Strabismus which is a misalignment of the eyes that usually is congenital, but could be caused by 3D. From personal experience I feel like there is a little strain every time I watch a 3D movie or play 3DS and I wonder if doing that every day or every time I watch TV would change my visual perception after a while. I definitely enjoyed your blog and I’ll keep reading about this topic.

    -Elias

  2. I really enjoyed your post Catie! After reading it, I became curious about how 3D devices cause your body to see the 3D images. In normal vision, your body takes the separate information taken in from each eye and resolves it to generate a 3D image.

    It turns out, 3D portions of films are very similar. In 3D movies, there are two different images being displayed on a screen at once. Without appropriate glasses on, this may just make the screen look like a blurry mess, but by putting on the lenses, the images are filtered so only one enters each eye. The disposable 3D glasses of our childhood typically feature lenses that are two different colors (often red and blue). The two images on the screen are tinted to these colors to allow the filters to select for one or the other. Some more modern 3D venues use differences in polarization of projected films and lenses that filter for these differences. By wearing the glasses, our eyes see two distinct images and perceive depth that we would not were the two eyes receiving the same information.

    What about the Nintendo 3DS? You do not have to wear special glasses to utilize the 3D images of this gaming system. I found (http://www.joystiq.com/2010/08/12/the-3dss-glasses-free-3d-explained/#continued) to be helpful in explaining. Rather than filtering to only allow your eyes to see specific images, the Nintendo 3DS alternates the angle at which light is released to create separate images that are focused toward each of your two eyes. This is why the 3D effect of this gaming system only is apparent if held at the correct angle and distance from your eyes.

    Some more information can be found at the following sites as well.

    http://www.3dglassesonline.com/learn/how-do-3d-glasses-work
    http://www.tomsguide.com/us/Nintendo-3DS-3D-Glasses-DS,news-6237.html
    http://www.howstuffworks.com/question360.htm
    http://www.rainbowsymphony.com/how_do_polarized_3d_glasses_work.html

  3. I enjoyed a lot reading this post! It is surprising to learn that Nintendo 3DS would potentially help doctors diagnose eye diseases in their early stage. It is also interesting to learn that why using laptops for a long time would cause eye problems. But here is my question: in some TV commercials the dealer says that their TVs have a refreshing rate of 100Hz (100 frames/sec) and are better than those with 50 Hz refreshing rates because it is no longer “winking”. Why is that? Isn’t that a higher rate of refreshing means your eyes need to refocus a lot more times?

    Talking about the 3D technology, I think it is an amazing technology breakthrough that takes advantage of how human body works. Here are the links of some “naked eye 3D” shows. The mechanism of the 3D effects in these shows should be different from Nintendo 3DS because here light is projected to a “screen”, whereas for 3DS light is projected from the screen. I am not sure how they make it, but the shows are very cool:

    http://v.youku.com/v_show/id_XMzIwNzIyNDQ4.html

    http://v.youku.com/v_show/id_XMzIxMTkzOTgw.html

    http://v.youku.com/v_show/id_XMjkzMDQ2MjUy.html

  4. I’m not sure I know the answer, but my best guess is that the higher rates being better has something to do with whether or not the eye notices the refreshes. When the camera reel first starts in the movie theater you can see where the separate slides are, but when they go fast enough you can’t tell that they are actually refreshing and it looks like continuous motion. I think that it would apply for computers and TVs. If you can notice the refreshes your eyes are going to have to adjust, but if they blend together as one motion maybe they don’t need to for each refresh.

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