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You are here: Articles --> 2016 --> Protecting yourself from injury (Part III)
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Protecting Yourself From Injury While Using a Computer—Part 3: Eye Strain

by Geoff Hart

Editor’s note: This series of articles is taken from Appendix II of Geoff’s book Effective Onscreen Editing, 3rd edition, which was published in May 2016. Republished for Corrigo with the author’s permission.

Previously published under the same name in Corrigo, newsletter of STC's Technical Editing SIG. Click here to read Part I; click here to read Part II.

he more you use your computer, the greater the risk you’ll encounter a repetitive-stress injury (RSI) such as carpal tunnel syndrome. That’s not because computers are inherently harder on your body than (say) jogging, but rather because the problems are subtler and develop over longer periods. (Unless you jog 8 hours per day.) RSI results from overuse of a body part without giving it time to recover, so it’s also called an overuse injury. Given how much time modern editors spend at the keyboard, overuse is surely a risk. The most common problems fall into three categories, each of which will be discussed in separate blog posts:

These articles provide the information you’ll need to understand these problems and take the necessary steps to protect yourself.

Get professional advice: The information in these articles was reviewed by medical and ergonomics professionals, but it is not a substitute for professional advice. If you’re experiencing a problem, or worried that one may be developing, seek medical advice now. Don’t wait for the problem to become serious. It’s easier and less painful to prevent an injury than it is to treat it. 

Eye strain

Our eyes work best when they move around and focus on objects at varying distances, so spending a day staring at a computer monitor will clearly stress them. Optometrists advise taking frequent breaks to gaze at something more distant than your monitor to stretch and exercise the muscles that help your eyes focus. Taking breaks is easiest if you have a window with a nice view, but even if you work in a cubicle farm, you can walk outside during your coffee break to encourage your eyes to focus on moving targets at varying distances. Here are a few other suggestions:

Visual ergonomics: The Vision Council offers a downloadable PDF guide, Eyes Overexposed: the Digital Device Dilemma, that explains some of the problems with the modern digital life, and provides suggestions on some relevant solutions.

Help your eyes focus

Your monitor should generally lie at least arm’s length from your body. That’s far enough you won’t strain to see the whole picture, but not so far you’ll squint to see the text. Although no one distance works best for everyone, start with this distance and adjust it until you find a comfortable match for your eyes.

If you wear eyeglasses or contact lenses, ask your optometrist about computer versions optimized to help your eyes focus at the distance of your monitor. Multifocal lenses (e.g., bifocals) let you focus comfortably at a range of distances by looking through different parts of the lens, but not everyone finds these glasses comfortable. If, like me, you rarely look away from the screen while computing, it may be more effective to get corrective lenses specifically designed for computer use. Use a second pair of glasses for distance viewing while you’re driving a car or walking around.

Crisp pixels, relaxed eyes

A high-quality monitor is a great investment in protecting your vision. Particularly if you work with small fonts, staring at fuzzy text all day fatigues your eyes, which must work harder to focus. CRT monitors (the deep, clunky ones) provide adequate sharpness, but LCD monitors (the really thin ones) are now a much better bet: the prices are affordable, the resolution is so high it’s hard to see the pixels, the screens are much larger than CRTs for the same price, and there’s none of the flicker that exists with even the best CRTs. As a result, I no longer consider CRT monitors a good option for most editors, and have removed my description of this old technology from the third edition of my book. Ideally, save up enough money to afford an LCD monitor large enough to display two standard pages side by side at 100% magnification. A widescreen 21- or 24-inch monitor will accomplish this and you’ll find yourself working far more efficiently using it.

Large versus multiple monitors: There are distinct advantages to having two or more large monitors connected to your computer, but if space is tight, a single large monitor is a good compromise.

Irrespective of the size and type of monitor you use, experiment with resolutions and display characteristics, as described in Chapter 4 of Effective Onscreen Editing, to optimize the display for your eyes. Test the various available typefaces to see which ones display most crisply on your screen. Some believe that certain typefaces (e.g., Verdana) are easiest to read on the screen, but in my experience, the best typeface is more a personal preference than an objective and absolute recommendation. In short, let your eyes be the ones to judge which typeface works best for you. Once you’ve chosen a legible typeface, test different sizes to see which ones are easiest on your eyes; an 11- or 12-point font can cause less eyestrain than the 10-point fonts many people use.

If you’ll be doing onscreen proofreading and the type size is fixed by the design specifications, don’t assume that you’re forced to examine the text at that size. Most software lets you zoom in on the display, thereby enlarging the text without affecting the design. Of course, this works best if you own a large monitor, so this is another reason to buy the biggest monitor you can afford and that will fit on your desk.

Stamp out flicker

LCD monitors don’t suffer from the flickering that besets even high-quality CRTs. Nonetheless, check the manual for your monitor to see whether it offers a range of refresh rates (more accurately, “frame rates”). The pixels don’t have to be constantly renewed, so the only flickering occurs when you change pixels. In editing, this is most serious when you scroll through a document. The common refresh rate of about 60 Hz is fine for most viewers, but monitors with rates of more than 100 Hz are now available and show less flicker during scrolling. The backlight used to illuminate the screen is more likely to cause significant flicker. Fluorescent backlights suffer more from this problem than LED backlights, so if you can afford the (usually small) price difference, opt for LED backlighting.

There are several additional features to consider when you choose an LCD monitor:

Arrange for suitable lighting

Monitor problems can be exacerbated by traditional fluorescent lights. These flicker slowly enough that many people can see the flicker (me, for instance), and because the light flickers at a different frequency from the monitor, this produces a “beat” that can strain your eyes further. Traditional incandescent light bulbs don’t flicker, but these are fast disappearing. Compact fluorescent lights are a better solution, since they flicker much less noticeably than traditional fluorescents and draw considerably less power, while providing comparable levels of light. LED lights are an even better choice if you can find ones bright enough for your office.

Whatever lighting you choose, arrange the lights and computer to eliminate reflections on the screen from lamps or nearby windows. Reflections create glare that fatigues your eyes by forcing them to concentrate harder to look past the glare. Positioning a screen to face away from windows and lights or adding a glare-reduction filter can help. Sometimes all you need to do is adjust the monitor’s tilt so the reflections are directed away from your eyes. Although working in a darkened room might seem a viable alternative, that’s usually a bad idea; the excessively high contrast between the bright screen and the dark room can increase eye strain.

If your LCD screen flickers, the most likely cause is that the backlighting is failing, that you have a damaged cable, or that you’re experiencing power fluctuations. Installing an uninterruptible power supply (a UPS) can eliminate many power problems, but not ones that originate in the monitor or your computer. Since you should be using a UPS to protect your computer, installing one can help eliminate power fluctuations as the cause of the flicker. Cables are easy to replace and not too expensive; moreover, if the cable is detachable, you can bring it to a friend and connect it to their monitor to see if the cable needs to be replaced. If neither the power supply nor the cable is responsible, you may need to repair or replace your monitor.

Computers aren’t “tear jerkers”

There’s evidence that we blink less often while staring at computer monitors, and this probably causes the common complaint of dry eyes at the end of a day of computer use. The solution, of course, is to use nature’s own lubricant for your eyes: remember to blink while using your computer, thereby moistening your eyes. Taking regular breaks will help, because you’ll blink more often when you’re not looking at the screen. Working in a room with appropriate humidity levels also helps. To keep humidity at comfortable levels, grow plenty of household plants in or near your office. In unusually dry climates, consider installing a humidifier.

If your eyes remain dry, consult your optometrist to confirm that there’s nothing medically wrong, and ask them to recommend a good brand of eye drops; ideally, ask for a brand without preservatives, which can irritate the eyes. Use a kitchen timer or your computer’s reminder program to remind you to periodically moisten your eyes or take breaks.

Solutions

The good news about most overuse injuries is that you can do a lot to protect yourself. See your doctor and your optometrist at least annually so they’ll have a chance to detect any slowly developing medical problems you might miss. Between visits, pay close attention to your body so you’ll know whether you’re beginning to have a problem that you can solve yourself or one that will require professional help. An RSI expert will evaluate more than your symptoms; they’ll also ask you about your lifestyle, your work habits and work environment, and various other factors related to the problem. But it’s far simpler and much less painful to head off problems before they require treatment.

In summary, here are things you should be doing to protect yourself and minimize the risk of problems or their severity if they arise:

Don’t forget the “repetitive” aspect of RSI: If you spend long enough doing anything, you’ll grow tired, and if you push past the point of fatigue, you’ll greatly increase the risk of injury. Take a break from the computer and enjoy the other things that life has to offer.

In moderation, of course.


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