July/August 1998

How are your eyes feeling today?

Do your eyes ache as you work at your computer? Do your eyes need time to refocus when you look away from the monitor? Do you experience headaches, fatigue, or neck and back pains after working on the computer all day? If you answered yes to any of these questions, you're not alone. "The National Institute of Occupational Safety and Health (NIOSH) estimates that 88% of those who work at computers three or more hours a day suffer from eyestrain." (Computerworld, May 25, 1998)

The American Optometric Association even coined the phrase Computer Vision Syndrome (CVS) to cover everything from eyestrain to blurred vision, light sensitivity, headaches, fatigue, and neck and back pains.

It is not the computer video display terminal (VDT) that causes the problems, rather it's the way we use them. The American Academy of Ophthalmology points out there is no convincing scientific evidence that computer VDTs are harmful to the eyes. But when looking at a computer screen, people tend to blink a lot less and the text on the screen tends to be high in the visual field so you open your eyelids more. Both of these situations contribute to dry eyes which can lead to eyestrain. Also, many people work in awkward positions, (e.g., leaning forward) while at the computer and don't take enough breaks.

Get an eye exam

You need to determine whether your vision is satisfactory for computer work. Even if you don't normally need glasses, you may need them for computer work. And you should be aware that there are prescription computer-specific glasses. Be sure to tell your optometrist or ophthalmologist about your computer work and environment (monitor height relative to your eyes, glare, etc.)

Take your breaks today

If you gaze at something too long, your eyes can tire. And eyes are strained more by close viewing than by distant viewing. You should take frequent, quick breaks to refocus your eyes. One suggestion is to look away from the computer screen about every 10 minutes, and refocus as far as possible into the distance for 10-30 seconds. Another source suggests a "20/20 rule" — every 20 minutes look 20 feet away for 20 seconds.

You also need to take longer breaks or schedule your work to allow different visual tasks. NIOSH recommends a rest break of 15 minutes for every two hours of moderately demanding VDT work, and a 15-minute break for every hour of intensive VDT use. Schedule your non-computer work as breaks away from your computer. Better yet, move to another location during your rest break. You will lessen the muscular load on both your eyes and body and have an opportunity to interact with others.

If you need a reminder to take breaks, you may want to install ergonomic software or place a template on your keyboard. You can purchase software that pops-up a window on your screen at regular intervals to remind you to take a break and usually suggests exercises to perform. For more information see the AliMed Ergonomic Web site.

Throughout your work time on the computer remember to consciously blink more often to lubricate your eyes and prevent them from drying out.

Check your environment

Here are some work space suggestions that can help prevent or reduce eyestrain:

Put the monitor at the proper distance and height. The monitor should be at least 20 inches away from your eyes when you are sitting straight on to the keyboard and monitor with your back against your chair. A good guideline is to have the monitor around arm's length away. The top line of text on the screen should be at eye level or lower.

Place reference material as close to the screen as possible and at the same height. This will minimize head and eye movement and focusing changes.

Minimize glare and reflections. Watch out for direct glare (a light source shining directly in your eyes) and reflected glare on the computer screen. Place the monitor at a right angle to a window or other bright light source. Also, make sure your office lighting is comfortable for VDT use. You may want to lower light levels (modify the office lighting and /or use window blinds or shades) and add task lighting for reading print materials. If it is not practical to modify your office lighting, you may need to use visors and filters on the computer monitor to eliminate glare and reflections. You can even buy anti-glare filters that magnify the image.

Dust your screen! The computer screen is a good dust collector and should be wiped often with an anti-static cloth to improve visibility.

Sources:

• "A Dozen Things You Should Know about Eyestrain" and "'Conventional Wisdom' vs. Current Ergonomics" papers on the Office Ergonomics Web site
• "Computers and Eye Strain." American Academy of Ophthalmology.
• "Ergonomics, Focus on Computer-related Eyestrain," by David Wolff. Computation Center Newsletters, Oct/Nov 1997. Iowa State University.
• "Eyes of the Beholder," Rochelle Garner. Computerworld, May 25, 1998, page 74.
• Zap: How Your Computer Can Hurt You and What You Can Do About It. Sellers, D. and Roth, S. Peachpit Press, Berkeley, CA. 1994.

Other resources:

• "Office Ergonomics" video available for free checkout from our loan library. This 17.5 minute video covers everything from defining ergonomic terms to eye care to workstation setup.
• IBM's Healthy Computing Web site (information on all aspects of computing ergonomics and very good illustrations).

~ Pamela Peters

CIT Information is published by Communications and Information Technology - Computing section, Institute of Agriculture and Natural Resources, University of Nebraska-Lincoln. Newsletter articles may be copied and distributed for nonprofit, educational purposes only and the source must be acknowledged. Direct all correspondence to the editor, Pamela K. Peters (E-mail: pkpeters@unlnotes.unl.edu; Phone: 402/472-5630; FAX: 402/472-5639).

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