What is Computer
Vision Syndrome?
What
is CVS?
The
Problem
A
government agency, NIOSH, estimates that nearly 60 million Americans
suffer from computer eyestrain. If you spend hours each day in front of
a computer screen, you likely experience some symptoms of computer
eyestrain:
- Headaches
- Loss
of focus
- Burning/tired
eyes
- Double
vision
- Blurred
vision
- Neck
and shoulder pains
This
is caused by our eyes and brain reacting differently to characters
on the screen than they do to printed characters. Until now, normal eye
exams for near vision have resulted in eyewear suited for reading
printed material, not for viewing computer screens.
 
Our
eyes respond well to most printed material, which is characterized
by its dense black characters with well-defined edges which contrast
markedly from their light background. Healthy eyes can easily maintain
focus on the printed page.
Characters
on a computer screen, however, don't have this contrast, or
well-defined edges. These characters are brightest at their centers and
diminish in intensity toward their edges. Our eyes are unable to
maintain focus and remain on plane with these images. They instead
drift out to a point called the resting point of accommodation (RPA).
Our
eyes constantly move to the RPA, and then strain to regain focus on
the screen. This continuous flexing of the eyes' focusing muscles
creates fatigue and the burning, tired eyes feeling.
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