Computer Vision Syndrome (CVS)

Beyond Normal Eye Strain

Computer vision syndrome (CVS) is a temporary condition resulting from focusing the eyes on a computer display for protracted, uninterrupted periods of time. Some symptoms of CVS include headaches, blurred vision, neck pain, redness in the eyes, fatigue, eye strain, dry eyes, irritated eyes, double vision, polyopia, and difficulty refocusing the eyes. These symptoms can be further aggravated by improper lighting conditions (i.e. glare or bright overhead lighting) or air moving past the eyes (e.g. overhead vents, direct air from a fan). According to the National Institute of Occupational Safety and Health, computer vision syndrome affects some 90% of the people who spend three hours or more a day at a computer.

Dry eye is a major symptom that is targeted in the therapy of CVS. The use of over-the-counter artificial-tear solutions can reduce the effects of dry eye in CVS.

Asthenopic symptoms in the eye are responsible for much of the morbidity in CVS. Proper rest to the eye and its muscles is recommended to relieve the associated eye strain. Various catch-phrases have been used to spread awareness about giving rest to the eyes while working on computers.

A routinely recommended approach is to consciously blink the eyes every now and then (this helps replenish the tear film) and to look out the window to a distant object or to the sky doing so provides rest to the ciliary muscles. One of the catch phrases is the "20-20-20 rule": every 20 minutes, focus the eyes on an object 20 feet (6 meters) away for 20 seconds. This basically gives a convenient distance and timeframe for a person to follow the advice from the optometrist and ophthalmologist. Otherwise, the patient is advised to close his/her eyes (which has a similar effect) for 20 seconds, at least every half hour.

Decreased focusing capability is mitigated by wearing a small plus-powered (+1.00 to +1.50) over-the-counter pair of eyeglasses. Wearing these eyeglasses helps such patients regain their ability to focus on near objects. People who are engaged in other occupations - such as tailors engaged in embroidery can experience similar symptoms and can be helped by these glasses.

CVS   Wikipedia

June 17, 2008 - FOX News

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.

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. 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.