A 26-year-old man who works for a telecommunications firm in Fort Lauderdale, Fla., developed a severe sensitivity to bright lights, especially at night, forcing him to wear sunglasses around the clock.
In New York City a woman quit her job at a law office, saying "my eyes could simply not endure the pain any longer. After a few hours my eyes would sting, water and finally swell so that I could barely keep my eyes open. I'm 30 years old and feel like 75."
A 41-year-old computer technician in Minnesota had to get six prescriptions in 10 months to increase the lens strength in his glasses, yet he still complains of headaches that last a week.
These three people are among thousands of video display terminal (VDT) users who have developed eye problems.
Nearly 60 percent of all VDT users experience eye problems, according to the National Association of Women Office Workers (NAWOW), which recently performed a study of 423 VDT users. Nearly half of those surveyed said since using a VDT they had been diagnosed as needing glasses or have needed a more powerful prescription.
Similar complaints come in daily, according to NAWOW and the American Optometric Association, as the number of VDT users continues to increase. That number has doubled every year since the late 1970s, when VDTs were first widely used in homes and offices.
"It isn't known that VDTs cause eye problems," says Dr. Michael Smith, chief of motivation and stress research at the National Institute of Occupational Safety and Health (NIOSH). "What is known is that VDTs can aggravate existing problems."
That may explain why VDT users have experienced migraine and weeks-long headaches, temporary loss of focal ability, burning and swollen eyes, and have been required to wear bifocals, trifocals and stronger lenses while using a VDT.
The extent to which VDTs cause these problems won't be known for decades. As National Academy of Sciences researcher Dr. William Stark puts it, "people who use VDTs are our guinea pigs."
Approximately 10 million American workers use VDTs daily. By 1990 that number will be 20 million, and by the turn of the century 40 million people -- nearly half of all U.S. workers -- will use VDTs, NIOSH estimates.
"It's well documented that VDTs cause acute visual complaints," Smith explains. "However, there have been no chronic studies of these problems, meaning studies done over a long period of time to a wide range of people."
Smith, like many researchers, says he is skeptical about conclusions from large-scale research projects conducted in the 1980s on physical and mental effects of VDT use. VDTs were invented in the early 1940s and used mainly for military purposes until the late 1970s.
Video display terminals were adapted from televisions, and "therein lies the problem," says Stark, a professor of physiological optics and engineering science at the University of California at Berkeley. He helped write a 1982 report for the National Research Council on VDTs and vision.
Televisions "were designed for large moving objects to be viewed at a distance for a short period of time," Stark says. "We found VDTs are very bad . . . they're not legible." He says that even a photocopy of a printed letter is sharper than the same letter on most VDT screens.
Environmental factors also contribute to eye strain caused by VDTs. Overhead office lighting often causes too much glare for the lime green characters of a video screen. Ideally, VDTs should be used in a dimly lit room, just as movies are viewed in a dark theater.
VDTs make some people more photosensitive (sensitive to light) than others, like the man who worked for a telecommunications firm and was forced to wear sunglasses after too much VDT work. No one understands this phenomenon, say both Stark and Smith.
Although nobody really knows what causes myopia, some eye experts believe close work on VDTs may cause nearsightedness.
Francis Young, a psychologist at the State University of Washington, believes that working on a computer terminal can cause myopia because it is "near work" -- requiring one to focus on objects close to the eyes -- not because the computer emits any radiation. "We have known for a long time that near work causes myopia, and I think working on a computer terminal qualifies as near work."
Not everyone agrees.
"There is no hard evidence that near work has any effect on the refractive state of the eye," says Dr. Elio Raviola, professor of anatomy at Harvard Medical School. "But it's very possible.
"The point is very little is known about the causes of myopia," says Raviola. But he points out that "there are very good studies that indicate there is a tendency in the generation that has been exposed to television to have a higher rate of myopia."
Those findings may apply to computers as well as television. Young cites studies from the National Center for Health Statistics that show in 1900, 13 percent of the population was myopic. "Today approximately 40 percent of the population is myopic, and about 15 percent more people became myopic around 1955, when television came into widespread use," he says.
Both Young and Raviola say they are concerned about the rise of nearsightedness in children. "It used to be that only studious children who read a lot developed myopia," explains Raviola. "Now children from all types of backgrounds, even kids who never read but love to play computer games, are becoming myopic. It's very disturbing."
Other eye problems have also been linked to computer terminals, but the connections have remained controversial because of a lack of scientifically acceptable studies.
One study, conducted in 1980, concluded that low levels of radiation emitted by VDTs, which includes word processors, can cause cataracts. The National Academy of Science's 1982 summation of studies done on VDT radiation and cataracts criticized the study because it examined only 10 cataract patients, resulting in two "small reports."
The NAS panel of experts also pointed out that the study was never "published in a refereed scientific journal." In a refereed journal, the validity of a research report is independently evaluated by several other experts in that field. The panel concluded that "although no scientific medical study . . . is yet completed, available data do not support the claim" that VDTs can cause cataracts.
The effect of VDTs on eyes remains a controversial topic. While some people say they develop eye problems from the terminals, others experience no difficulty.
"I worked with VDTs for years and I've never had a problem," said Susan Galetar of Arlington. "People have always gotten eye strain from work and reading too much, even before there were VDTs."
Even doctors and researchers seem evenly divided on the question.
Meanwhile, Janice Blood, of NAWOW, says complaints from office workers using VDTs continue to increase.
"For the first time we had a worker receive confirmation from a doctor that the VDT caused her eye disease," said Blood. "She's elderly and went to 10 doctors before one would confirm it . . . Now she's trying to collect workman's compensation and can't." But, Blood concedes, the case "is questionable." Resources
* NAWOW has a daytime hotline for VDT users to register complaints and find more information: (216) 566-1699.
* The American Optometric Association has written a pamphlet, "Vision and the VDT Operator." To receive a copy, send 25 cents and a self-addressed, stamped envelope to the AOA Communications Dept., 243 N. Lindbergh Blvd., St. Louis, Mo. 63141.