Computer Vision Syndrome
(CVS) - Beyond Normal
Eye Strain
You've just put in a 10-hour day, most of it in front of a computer screen. Your eyes feel hot and tired and you've got a headache. Your vision may be blurry.
It's a familiar scenario and it's got a name: Computer Vision Syndrome (CVS).
Despite the large numbers of Americans affected by long hours at a computer " an estimated 15 million " few have heard of CVS.
Occasional signs of eye strain are normal. But if symptoms multiply, affecting comfort and productivity, you may have CVS.
"It's an insidious problem," explains optometrist Dr. Barry Tannen, an associate clinical professor at the State University of New York College of Optometry.
Just like other muscles in our body, muscles in the eye can become tired from overuse.
"Staring at a computer screen all day is stressful and straining," says Ellen Kolber, an occupational therapist.
For one thing, images on the screen aren't solid. Rather, they are pixilated - composed of many dots that make a letter dark at the center and fuzzy on the edges.
"Our focusing system doesn't quite know how to respond to that," explains Tannen.
Eyes also get a workout focusing and refocusing as they glance back and forth from a document to the screen.
Glare from screens and bright office lighting are also issues. "For computer use, over-illumination is deadly," says Tannen. Eyes become hot and tired; some people develop photo sensitivity that can trigger headaches.
Computers should be illuminated from the side, not from directly in front or back, says Kilber.
Then there's the dry-eye problem. "A computer is such a compelling target, we forget to blink," Tannen says. People normally blink 14 times per minute, which helps lubricate eyes. Computer users blink five times per minute.
Jan Paschal, a copy editor for Reuters, says she spends at least seven hours a day at her computer. "I've learned to be very protective of my eyes."
She uses an eye wash four times a day and takes visual timeouts. "Even if I'm not taking a break away from my desk, I look away from my screen," she says.
Not surprisingly, a whole industry is springing up to address CVS. Bausch & Lomb has introduced "computer eye drops." There's even a "Computer Eyestrain Journal" on the Web. And optometrist Dr. Dennis Ruskin from Toronto has developed a reference manual on CVS and a software program that tells you when to take breaks.