Fergus Falls Optometric Center
"Family Eyecare from the Eyecare Family."
Dr. Mark D. Olmsted and Dr. Christine A. Olmsted
117 E. Lincoln Ave.
Fergus Falls, MN 56537
Appointments: 218-736-7555

Computer Vision Syndrome - 13 Feb 2005

Computer Vision Syndrome
13 Feb 2005

Computer Vision SyndromeFor the last 15 years or so, it seems that more people are using a computer for at least part of their day. Whether it be the main tool of one's office environment like 70 million Americans or just an internet surfer stomping someone from "Down Under" in an online backgammon match (my Achillesheel in the world of free-time management), computers are a big part of our lives.

While we never think about it, there is a lot going on visually when we are doing nearpoint work. Our extraocular muscles, which control eye movement, must aim both eyes to the exact same point for binocular vision. Additionally, when reading they must move our eyes in unison across the reading material, while maintaining binocularity. Simultaneously, our intraocular muscles must work to change the shape of the eye's natural lens for close work to be in focus. Our eyelids, which are on "autopilot", must blink every few seconds to keep the tear film evenly spread across the eyes. Unfortunately, while concentrating on reading we keep our eyes much wider open and don't blink quite as often as normal. This dries our eyes, decreasing comfort.

Computers add an extra twist to these visual demands. Since the characters on a monitor are formed from numerous pixels of light, our eyes get more fatigued than when looking at crisp black print on paper. Since there is a "softer" edge to computer print with less of a contrast, our eyes tend to have to "search" more for that obvious focal point.

These factors all contribute to what is now known as "computer vision syndrome" (CVS). Our eyes are doing a lot of work when reading. If anything is not optimum, such as an outdated eyewear prescription, poor lighting, etc., one can get eyestrain and headaches.

How can we try to maintain eye comfort at a computer?

First of all, a person must have the correct prescription eyewear for computer tasks. Even a small uncorrected error that many people would normally do well without in other situations can bother a computer user. So wear your best nearpoint visual correction, which is often different than your driving prescription. Special occupational computer glasses such as "Access" and "Office" are excellent for this.

Secondly, decreasing reflections from the computer screen is big. Factors that affect this are room lighting, monitor illumination, and the tilt of the monitor. Putting a glare screen on the CRT helps a lot. Close the window shades. As far as glasses go, antireflective coatings are available, which greatly reduce this glare.

Thirdly, try to make your workstation mimic the position you would hold a book when reading, down at about a 10-degree angle. We don't just hold reading material lower and slightly tilted because of arms comfort. Our eyes work binocularly much more comfortably in that position. Also, our tear film is preserved for longer periods of time when looking down a bit.

Lastly, to decrease CVS, practice good "visual hygiene". Try to do a different task away from the computer every 20 minutes or so. If you can't get away, just look off in the distance farther than 20 feet for a moment. Take "blink breaks" and use artificial tears to keep your eyes moist.

It's my turn for some visual hygiene. After writing this article, my eyes feel the need for a break. I better do something else for awhile before I chase down that Aussie for a backgammon rematch.

Dr. Mark D. Olmsted