Most people who use computers are aware of the risk of carpal tunnel syndrome from the keyboard, but now there’s also a risk to your eyes from the monitor.
A recent study showed that 41 percent of people who use computers for more than four hours a day have symptoms of Computer Vision Syndrome.
“This can be symptoms like eye strain, headaches, blurred vision, dry, irritated eyes, and even neck and back aches,” says James Sheedy, director of professional development for SOLA Optical USA.
There are two main causes of CVS: a diagnosable eye condition and something in the work environment.
“Many people have either binocular vision or eye focusing problems,” says Sheedy, who also heads the Computer Eye Clinic at the University of California. “These conditions do not cause problems for people as they go through their daily activities, but if you put them in front of a display and focus on one thing, their weakness in visual functioning will manifest itself into symptoms.”
The most common health problem associated with CVS is dry eyes. Studies show that your blink rate slows to one-third of normal when working at a computer. When you are reading a book, your eyes are half closed. When you are looking at a monitor, your eyes are wide open, creating a greater exposed surface and increasing the evaporation rate.
For people who use bifocals, the symptoms can show themselves in other parts of the body. The lower segment of the bifocal lens is designed for viewing distances of about 16 inches and looking downward. Unfortunately, that’s not where the computer screen is. Typically, the monitor is 24 inches away and higher up. As a result, a person wearing bifocals tends to tilt his or her head back and lean closer to the computer, resulting in an awkward posture that can cause backaches or neckaches.
Many of these problems can be fixed with specially designed lenses or a visit to the doctor. Environmental factors are something you can fix yourself.
Bright lights. “Most offices were designed when people were not using computers,” says Sheedy. “People were always looking down at their desks, so the lights were not in their field of view. With computers, the bright overhead lights are in your field of view.”
To see how much the lights affect your vision, look at a point across the room, then shield your eyes by making a visor with your hands. Most people notice a difference when the light is shielded from view.
Perform the same test using a file folder over the top of your monitor. If you can see it better, there are reflections on your screen.
“The best fix is some sort of anti-reflection filter, but if you’re on a budget, some tape and a file folder will do,” says Sheedy.
Location of the screen. “When you are doing visually intensive tasks, the body will get the eyes in to a location to do whatever needs to be performed,” says Sheedy. “The monitor should be dead in front of you, not off to the side. Twisting your body for long periods of time will lead to pain.”
The height of the screen is also important. Ideally, the center of the screen should be about 4 to 8 inches lower than your eyes.
“The good news is, most of these problems are largely treatable,” says Sheedy. “Almost all of the problems can be resolved through the proper management of the environment or of the eyes.”
Todd Shryock ([email protected]) is SBN’s special reports editor.
