You can
now add “computing” to the list of things at Duke that may be hazardous to your heath, in addition to alcohol,
cigarettes, marijuana, sleep deprivation, and bad eating habits. Believe it or
not, using a computer improperly can actually be very hazardous to your vision, permanently or temporarily. To protect your eyesight, it is very important that you understand why computing safely is essential in
your four years at Duke.
In a recent paper by Brian P. Rawson from IBM,
the author showed that using a computer improperly (2002) can lead to a condition known as Computer Vision Syndrome, or CVS. The American Optometric Association defines CVS as, “The complex of eye and
vision problems related to near work which are experienced during or related to computer use.” Some symptoms of this condition are: eyestrain, tired eyes, blurred vision, dry or irritated eyes, excessive
tearing, headaches, as well as neck, shoulder and back pain.
How it all works.
To really
understand what is happening in your body, let us think about the functionality of the eye and how it works. Rawson describes the lens of an eye as a magnifying glass that must be continually focused and refocused
as you look around. This work is done by a muscle known as the cilliary muscle,
which contracts and relaxes like any other muscle (2002), for instance, your bicep.
Your cilliary muscle can become quite tired when it darts between the computer screen, a paper on your desk, a friend
who walks in your dorm, and then back to the computer. This is analogous to lifting
weights, thus leading to eyestrain and tired eyes (2002). Therefore, it is essential
that when you take a break from writing that paper and surfing the web that you let your eyes rest by doing something that
isn’t too visually taxing, like having a relaxed conversation with your friend or roommate.
My stereo affects my computer?
Even if you
can’t take leisurely breaks from your work, there are several things that can be avoided to reduce CVS. First, try to avoid flipping back and forth between two documents that are not alike in color or geometry
(i.e. visual opposites), as it may be a large strain on your eyes because of the focusing and refocusing of your lens. Secondly, make sure that there are no large electronic devices (stereo, TV, amplifier
etc.), or electric cables running nearby, as they may cause the images on your computer monitor to be fuzzy and/or jittery.
Two case studies have shown that when monitors were near other large electronic
devices that the workers using them often complained of the symptoms related to CVS.
The reason behind the fuzzy and jittery images lies in electromagnetic interference, or VDT EMI. Such interference is a result of having an electronic device, like a stereo, that gives off a large magnetic
field near another object that gives off a different magnetic field. Your computer
monitor is often that other object. It has a smaller magnetic field, and is thus
affected by the larger magnetic field. The electronic components within the monitor
are now pushed by a new magnetic field in such a direction that they move back and forth very rapidly, causing blurry and
jittery images. The lens of your eye tries to make a definite edge to these images,
and thus is constantly focusing and refocusing- tiring the cilliary muscle.
But the way I’m sitting is comfortable right now!
Other than technological
problems, there are also some ergonometric, or posture issues that can cause the symptoms of CVS. When you are trying to adjust your eyes into a comfortable position, you subconsciously move your body
such that it will give you the best visual position. However, this may not be
the best position for you physically. After sitting in this position for a long
period of time, it may result in neck and/or back pain, as well as a headache, thus putting additional stress on your body. All of this makes you tired much faster than usual (2002). To solve this problem, make sure that you are sitting upright with your eyes far away from the screen,
at about 50 centimeters. If you can’t see from that far, increase the size
of the images and text on your screen, as squinting will hurt your eyes as well.
There is no crying when using a computer…
There are other
small things that can cause computer-related eye problems as well. You may find
that when you are trying to focus on an image on your screen that your eyes dry up fairly quickly, causing the symptom known
as “dry eyes.” This is a result of you not blinking as much when
focusing on that image, and then your monitor’s heat causing you to tear thus making you rub your eyes. To solve this, use a high resolution on your monitor and a large viewing area so that you don’t have
to do too much focusing on the image. Also, keep your screen clean from dust,
and make the light around you the same as your computer screen. This should diminish
the possibility of your eyes either getting too dry, or over-straining which causes pain.
So, now you know how to reduce the effects of
CVS while you are here at Duke. Whether you’re constantly online researching, or chatting with your friends, or writing
that paper you just can’t seem to finish- don’t forget about your eyes.
Your future will be very blurry.
Reference:
Rawson, B.P. Video Display Terminal EMI and Human Visual Response. 2002 3rd
International
Symposium on Electromagnetic Compatibility. 24 May, 2002.
(696-700)