For many people, working in front of a computer monitor means aching eyes, blurred vision and even migraines. Eye and vision problems are fast overtaking sore wrists and hands as one of the most frequently reported health-related complaints among the ever-growing numbers of people who spend time peering at a computer screen.

"There is no disagreement among experts that we're seeing more and more computer-related vision problems," said Dr. Kent M. Daum, an optometrist and professor at the University of Alabama School of Optometry in Birmingham who has written a number of papers on computer-related eye strain. "The eye isn't meant to close-focus all day. Doing so can lead to considerable problems."

An eye test given by Dr. Gary Tracy, an optometrist in Manhattan, used a simulation of the way people view computer screens.

So quickly have computer-related vision issues grown in the past year that the Occupational Safety and Health Administration of the Federal Department of Labor is considering incorporating these issues into the ergonomic guidelines that it is developing. "Right now, the standard targets people in manufacturing," said David Cochran, who directs the agency's work on the guidelines. "We're still wrestling with how to deal with offices and computer work stations."

Surveys cited by the American Optometric Association, an organization of 32,000 optometrists, indicate that 70 percent to 75 percent of computer workers have eye and vision problems.

"My eyes start to burn before I get far into the day," said Leah Krawetz, who runs a travel agency in St. Paul, Minn. "Right now, they are killing me, and no wonder—I'm working on an airline reservation from here to Birmingham, England, to Oslo, Norway, and back, all within a budget of $1,500 to $1,600. That's a guaranteed recipe for eye strain."

Blurred vision, along with aching, stinging eyes, is one of the most common complaints related to computer use.

"Some blurred vision comes about because of incorrect glasses or contact lenses," Dr. Daum said. "But that is not the only reason. The process of reading up close requires a muscular effort. People who challenge the muscle may have what are called spasms of accommodation. When they look up into the distance, the mechanism to focus is locked into place; everything seems fuzzy."

The fuzziness abates in about 15 minutes for a person in good health, he said, but if someone is worn down or continues to abuse the eyes with long periods of close work, "the eye cannot easily recover from the spasm or goes into involuntary spasm, a condition that's very hard to manage," Dr. Daum added.

Working in front of a computer may also induce other serious problems, Dr. Ronald Burd, director of ophthalmology at Albert Einstein College of Medicine-Montefiore Medical Center in the Bronx, said that computer monitors could occasionally trigger ocular migraines.

"Ocular migraine is not one disease process but instead a main highway with many roads to it," Dr. Burd said. "Some people are sensitive to red wine or blue cheese. Some small group of people who have migraines are very sensitive to the computer. I think perhaps the rhythmicity of the pixels in the display stimulates them."

Many optometrists view computer-related vision problems as a form of repetitive stress injury. "Symptoms are associated with repetitive muscular activity: frequent eye movement from documents to screen and from screen to keyboard," said Dr. Jeffrey L. Weaver, director of the Clinical Care Center for the American Optometric Association. "Just like other forms of R.S.I., the problems take time to develop and lots of time for recovery."

What can computer users do to guard against vision-related problems?

"Often users need a specific set of glasses for working at a computer," said Dr. Marcel J. Sislowitz, a Manhattan ophthalmologist and surgeon who draws a parallel between computer users and musicians. "If I give a piano player glasses suitable for reading a book, the glasses won't work—he'll have to lean forward to get the score in focus. It's the same for a violin player or a computer user. Both need prescriptions specific to the task."

More than half the people in the United States wear eyeglasses or contact lenses to correct vision, Dr. Weaver said, citing figures compiled by the American Optometric Association. "Conservative estimates put the number at at least 147 million."

For computer-related eye problems, doctors sometimes advise a step as simple as blinking, both for patients who wear corrective lenses and those who do not.

Dr. Michael Weiss, an ophthalmologist who practices at Columbia-Presbyterian Medical Center in New York City, explained how eye dryness played an important role in causing eyes to ache. "People get so involved with reading material on the computer that they don't blink regularly," he said. "It's very similar to what happens to drivers at night, when they concentrate on the road, forget to blink and experience eyestrain. The cornea isn't lubricated, and then they feel all sorts of sensations as they eye tells them they have a problem."

Dr. Weiss recommends that computer users close their eyes for breaks and blink frequently. Those who wear contact lenses, in particular, should use lubricants or artificial tears. "The most natural way to treat this is to take a break," he advised.

The newer generation of glare filters may also help; earlier ones were often accused of diffusing the images. Prof. Bob Beaton, a researcher at Virginia Tech in Blacksburg who has worked on glare filters for 15 years, said properly designed antireflection filters improved contrast, making the screen easier to see.

"Concern about eyestrain at the computer is universal," said Professor Beaton, who works on several international committees. "People often set brightness inappropriately, unaware that brightness and contrast work together. Turn up the brightness, and eventually the characters get fuzzier and lose contrast; the edges of the image thicken with brightness. A filter helps when circuitry on the computer can't make the screen bright enough for the contrast users want."

Professor Beaton said filters had little, if any, effect on the resolution of the display. "The newer models are basically as clear as glass and do not blur or fuzz the displayed image," he said. "They can attenuate or minimize reflections of a bright office or a bright shirt. Make sure light is not cast directly on the screen from windows, then adjust the monitor properly so that it is bright but sharp."

Looking down at the monitor, typically 10 to 20 degrees below the straight-ahead position of the head—not up—is also a good practice, said Dr. James Sheedy, a clinical professor of optometry at the University of California at Berkeley. "And if possible," he added, "make sure you're looking down at a large monitor with high resolution."

Humble steps like cleaning the screen may also be in order. "A thumbprint from peanut butter can give off a horrendous distortion," said Dr. Gary Tracy, a New York City optometrist who once came home from work to confront just such a smudge on his home computer. Dr. Tracy recommends even illumination in rooms where computers are used. "Working in the dark is hard on the eyes," he said.

If all else fails, a user might consider an eye test in which conditions working with a computer are simulated. Dr. Tracy occasionally uses such simulations in analyzing the eyesight of people who use computers for many hours daily. "Some people's eyes are thrown off by the fuzziness of letters in a computer display," he said. "In such cases, the test gives helpful information."

Dr. Daum is not sure that such tests lead to better prescription glasses or contacts. "I'm not sure it makes enough of a difference for such a test to be useful," he said.