Joanne Reitano is a professor of history at LaGuardia Community College in Queens. She writes wonderful books about the history of the city and state, and has recently been spending many hours — sometimes all day — at her computer to revise her first book, “The Restless City”. But while sitting in front of the screen, she told me, “I developed burning in my eyes that made it very difficult to work.”
After resting her eyes for a while, the discomfort abates, but it quickly returns when she goes back to the computer. “If I was playing computer games, I’d turn off the computer, but I need it to work,” the frustrated professor said.
Reitano has a condition called computer vision syndrome. She is hardly alone. It can affect anyone who spends three or more hours a day in front of computer monitors, and the population at risk is potentially huge.
Worldwide, up to 70 million workers are at risk for computer vision syndrome, and those numbers are only likely to grow. In a report about the condition written by eye care specialists in Nigeria and Botswana and published in “Medical Practice and Reviews”, the authors detail an expanding list of professionals at risk — accountants, architects, bankers, engineers, flight controllers, graphic artists, journalists, academicians, secretaries and students — all of whom “cannot work without the help of computer”.
And that’s not counting the millions of children and adolescents who spend many hours a day playing computer games.
Studies have indicated 70 to 90 per cent of people who use computers extensively, whether for work or play, have one or more symptoms of computer vision syndrome. The effects of prolonged computer use are not just vision-related. Complaints include neurological symptoms such as chronic headaches and musculoskeletal problems such as neck and back pain.
The report’s authors, Tope Raymond Akinbinu of Nigeria and Y.J. Mashalla of Botswana, cited four studies demonstrating that use of a computer for even three hours a day is likely to result in eye symptoms, low back pain, tension headache and psychosocial stress.
Still, the most common computer-related complaint involves the eyes, which can develop blurred or double vision as well as burning, itching, dryness and redness, all of which can interfere with work performance.
One reason the problem is so pervasive: unlike words printed on a page that have sharply defined edges, electronic characters, which are made up of pixels, have blurred edges, making it more difficult for eyes to maintain focus. Unconsciously, the eyes repeatedly attempt to rest by shifting their focus to an area behind the screen, and this constant switch between screen and relaxation point creates eyestrain and fatigue.
Another unconscious effect is a greatly reduced frequency of blinking, which can result in dry, irritated eyes. Instead of a normal blink rate of 17 or more blinks a minute, while working on a computer the blink rate is often reduced to only about 12 to 15 blinks.
But there are additional problems. The head’s distance from the screen and position in relation to it are also important risk factors. To give the eyes a comfortable focusing distance, the screen should be about 50 to 66 centimetres away from the face. The closer the eyes are to the monitor, the harder they have to work to accommodate to it.
In addition, when looking straight ahead, the eyes should be at the level of the top of the monitor. The University of Pennsylvania’s ophthalmology department advises that the centre of the monitor should be about 10 to 20 centimetres lower than the eyes to minimise dryness and itching by lessening the exposed surface of the eyes because they are not opened wide. This distance also allows the neck to remain in a more relaxed position.
Yet, in a study in Iran of 642 pre-university students reported in “Biotechnology and Health Sciences” last year, 71 per cent sat too close to the monitor for comfort, and two-thirds were improperly positioned directly opposite or below the monitor.
Improper lighting and glare are another problem. Contrast is critical, best achieved with black writing on a white screen. The screen should be brighter than the ambient light — overly bright overhead light and streaming daylight force the eyes to strain to see what is on the screen. A bright monitor also causes your pupils to constrict, giving the eyes a greater range of focus.
You might need to reposition the desk, use a dimmer switch on overhead lights, or lower window shades to keep out sunlight. In addition, using a flat screen with an anti-glare cover, and wearing glare-reducing or tinted lenses can help minimise glare.
Be sure to use a font size best suited to your visual acuity, and have your eyes examined regularly — at least once a year — to be sure your prescription is up-to-date. This is especially important for people older than 40 and for children who are heavy users of computers because visual acuity can change with age. Make sure, too, that your monitor has a high-resolution display that provides sharper type and crisper images. And clean the monitor often with an anti-static dust cloth.
Those who work from printed materials, moving back and forth from them to the screen, could minimise neck strain by mounting documents on a stand next to the monitor. If, like me, you use many different printed documents at the same time, consider getting special computer glasses — bifocal or progressive lenses with the upper portion ideal for screen reading and the lower designed for print distance.
While prevention is most important, if you have symptoms of computer vision syndrome, there are ways to reduce or eliminate them. Ophthalmologists suggest adhering to the “20-20-20” rule: Every 20 minutes, take a 20-second break and look at something 20 feet away.
Consciously blink as often as possible to keep eye surfaces well lubricated. To further counter dryness, redness and painful irritation, use lubricating eye drops several times a day. My ophthalmologist recommends products free of preservatives sold in single-use dispensers.
You can also reduce the risk of dry eyes by keeping air from blowing in your face and by using a humidifier to add moisture to the air in the room. And Reitano said her eye doctor also suggested applying warm moist compresses to her eyes every morning.
–New York Times News Service