There's relief for computing-related eye strain
May 25, 1998 - Web posted 2:00 PM EDT
by Rochelle Garner
eyes ache as I write this at my computer monitor. I have trouble keeping
the on-screen text from dancing an uncomfortable cha-cha as I type.
When I look away, my eyes need time to readjust their focus. I have
Computer Vision Syndrome (CVS).
Coined by the American Optometric Association in St. Louis, CVS is
a catchall phrase for everything from eye strain to blurred vision,
light sensitivity, headaches, fatigue and neck and back pains. The population
at greatest risk: people who intensively use computers for two or more
hours per day. (Can you say IT professional?)
"The eyes take the brunt of my computing experience, more than my
hands," says Ken Schiff, a software designer who frequently spends 15
hours per day at the computer. For Schiff, money is no object when it
comes to protecting his body against the rigors of computer use. But
despite a custom-built office, special lights even expensive trifocal
eyeglass lenses Schiff felt the burning effects of CVS.
Schiff isn't alone. The National Institute of Occupational Safety
and Health estimates that 88% of those who work at computers three or
more hours a day suffer from eye strain. Dr. James Sheedy, one of the
nation's leading researchers on vision and computer usage, figures that
15% of the 85 million eye examinations conducted annually in the U.
S. are the direct result of people staring at a monitor. That translates
into approximately $2 billion spent on eye examinations and computer-specific
"I was having really bad headaches right behind the eyes that seemed
to be getting worse the longer I sat at the computer," says Dale Carlson,
a staff engineer at Mylex Corp. in Fremont, Calif. After months of migraine-strength
headaches, Carlson had his eyes examined. The prescription: computer-specific
glasses. Today, Carlson's headaches have disappeared. And that's typical
with CVS symptoms, which, studies suggest, do not become permanent.
Heavy lifting The problem is that, for
a variety of reasons, staring at a computer screen is an incredibly demanding
"One reason it's so demanding is that the image you are looking at
is suspended in a box, with a reflective front surface," says Dr. Gary
Osias, an optometrist in San Lorenzo, Calif. "You know you can reach
the front screen, but that's not where the image is it's behind the
Another factor playing havoc with the eye: The pixels, or pinpoint
sources of light, that comprise the on-screen image. Use a magnifying
glass to exam each pixelated character, and you see lines broken up
by minute spaces with no sharp edges.
"That's a tough image for our focusing system to look at," says Jon
Torrey, vice president of marketing at PRIO Corp. in Portland, Ore.,
and co-inventor of the PRIO diagnostic tool used to prescribe computer-specific
glasses. "The eyes are inherently unable to hold that fuzzy image, and
revert to a spot behind the screen, called the resting focus. And the
whole time you're looking at the monitor, the eye constantly tries to
regain focus then drifts out again."
That resting focus, by the way, varies by person from about 20 inches
out to infinity.
"If your resting focus is at two and a half feet, then you won't have
too big a problem," says Torrey. "If it's at infinity, though, you will
be one unhappy camper."
The trouble is, a host of environmental issues not just the monitor
affect our vision. Staring at a monitor that's too high exposes more
of the eyeball, causing the eye to dry out. A screen placed outside
the optimal 18- to 24- inches distance from the eyes places undue strain
on our vision.
Glare, reflections and overhead light that's brighter the light emitted
by the monitor will all force the eyes to worker harder than is comfortable.
And when we can't see comfortably, we unconsciously contort our bodies
to get a better view. And that that can lead to painful and permanent
damage to our neck, shoulders, arms and wrists.
"The body follows the eyes, and that means you have to take a holistic
approach to setting up a workspace that's comfortable and productive,"
says Feride Biri, U.S. Ergonomics Program Manager at Sun Microsystems,
Inc. in Mountain View, Calif. "For many people, correcting one thing
in their workspace makes all the difference but that one thing will
be different for different people," says Sheedy. "And for many people,
it's a shotgun approach that works."
Schiff opted for the shotgun method, transforming his Union City,
Calif., office into an ergonomic palace. "I am a poster boy for what
to do at home," he says. Schiff's chair is a throne of ergonomic adjustments,
fitting his proportions like a fine Armani suit. Track lighting suffuses
the office with soft, indirect light. His three monitors pamper the
eyes with tiny dot pitch, sharp resolution and speedy refresh rates.
The monitors are low, forcing him to cast his eyes down the requisite
20 degrees the better to keep eyes blinking and moist.
But still his eyes bothered him. And then Schiff heard about special
computer-specific glasses made by Prio Corp. in Portland, Ore. Like
his trifocals, these are prescription glasses. What's different? The
diagnostic tool clips onto existing diagnostic equipment in a doctor's
exam room and simulates a computer monitor. While a patient looks at
the PRIO tester, a doctor uses a retina scope to see where the patient
actually focuses. Schiff says he now sees more comfortably.
His former problems highlight the salient point about eye care and
computer use: Try everything you can think of to make yourself comfortable.
Pull down the blinds, dim the lights, lower the monitor, sit up straight
and tall. Because when the body follows the eyes, the eyes can take
it down a road nobody should travel.
For your viewing pleasure: Six tips for reducing eye strain
(Source: Health and ergonomic professionals interviewed for this story.)
- Glare. While looking at the computer screen, use your hand to shield
your eyes from any light sources in your room: lamps, windows, whatever.
If you feel an immediate relaxation or soothing, you have a glare
problem. Draw the blinds or wear a visor while working.
- Light. Ideally, ambient light should have the same perceived luminance
as the monitor itself. Too many overhead lights? Try disconnecting
- Reflection. Can you see yourself in the monitor? Do your eyes feel
better when you place a manila folder on top of the monitor to block
reflections? If so, tape the folder to the top of the monitor, giving
it that sporty visor look.
- Monitor distance. Ideally, the monitor should be placed 18 to 26
inches away from your eyes when you sit flush against the keyboard,
your back against the chair.
- Monitor height. Again, ideally, arrange the monitor so that the
top line of on-screen text is at eye level. Placing a monitor too
high exposes more of the eye, causing it to dry out.
- And, oh yes, DUST THE SCREEN. Staring through the yuck that coats
the monitor places extra stress on the eye.