Computer vision syndrome
More than 143 million Americans work on a computer each day, with 88 percent of them suffering from computer eye strain, according to estimates. In addition, nearly 54 million children work at a computer each day either at home or in school.* Prolonged computer use can stress a child's eyes and impact his or her vision development
 What is Computer vision syndrome?
If you or your child spend more than two hours each day in front of a computer screen, you likely experience some degree of computer vision syndrome (CVS). Symptoms of CVS include --
- Loss of focus
- Burning/tired eyes
- Double/blurred vision
- Neck and shoulder pains
 What Causes Computer Vision Syndrome?
CVS is caused by our eyes and brain reacting differently to characters on the screen than they do to printed characters. Our eyes have little problem focusing on most printed material, which is characterized by dense black characters with well-defined edges. 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 (pixels) are brightest at the center and diminish in intensity toward their edges. This makes it very difficult for our eyes to maintain focus and remain fixed onto these images. Instead our eyes drift out to a point called the "resting point of accommodation" or RPA.
Our eyes involuntarily 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 that is so common after long hours at the computer.
- Frequently Asked Questions on Computer Vision Syndrome