COMPUTER USE AND VISION

So you work on a computer…

For years, the number of complaints of computer related eyestrain, backaches, headaches, and muscle fatigue have been increasing. What has not increased is the authoritative information on their causes and how to reduce or alleviate these problems. My hope is that I can provide some basic information and advice to reduce the strain and stress on the computer user.

Getting rid of that I've-been-working-on-a-weeklong-computer-project feeling isn't difficult. It just takes a few steps and a few changes. Let's take a look at some of the main problems and how to solve them.

1. Screen Glare: Glare is one of the main problems associated with computer use, and one of the easiest to fix. Since the front surface of the monitor is flat, light can easily reflect from this surface into your eyes. How can you tell if you have glare? Simply turn off your monitor. If you can see reflections of light in the screen, you have glare. This can affect you more than you think.

   Reflected images on the computer screen, perhaps a window or a lamp, will cause the eyes to focus back and forth between the computer screen and the reflected object. This affects how well you see what is on the screen and will tire the eyes rapidly, preventing them from seeing clearly as the day progresses.

   Reducing or eliminating screen glare is simple and easy. The most important prevention step is the use of an anti-glare filter, regardless of the type of monitor you are using. The filter fits on the front of the monitor and effectively reduces glare to minimal levels. But don't be fooled on price. The better anti-glare filters cost a little more but are well worth the added quality. Also, make sure that your desk has the office windows to the side, rather than to the front or behind, where the light can't shine directly onto the screen.

2. Office Glare: This type of glare doesn't reflect off the screen but can either reflect off of items in your office or can be caused by light shining directly into the eyes. These reflections increase the amount of light entering the eyes. When light levels become too high for you to tolerate you try to decrease the amount of light by squinting.

   The easiest way to tell if direct office glare is a problem is to simply put your flat open hand over your brow and then on each side of your face. If in any of these positions you feel more comfortable, office lighting including windows, lamps and ceiling lighting needs to be changed either in position or amount.

3. Monitor Height: The height of your monitor can also contribute to tired, strained eyes and appearance.

   Ideally, the top of the monitor should be below your straight ahead line of sight. Many computer users erroneously place the monitor on risers, books, platforms or even on a shelf because they were told that a higher placed monitor allows for proper body posture. While body posture is very important, what is not considered is visual posture. It is far easier for your eyes to focus for near work while looking downward, rather than straight ahead. So, the higher the monitor, the harder it is to focus.

   In addition, as your eyes look higher they open wider. This exposes more of your eyes for extended periods of time. The result is more tear evaporation, and the red, stinging, puffy eyes that follow.

4. Monitor Distance: The distance between the screen and you can add to focusing problems and strain.

   The closer the computer monitor is to you, the more effort it takes to focus on the screen. This increased strain, over time, can create a focusing lock and result in blur when looking far away from the monitor. Another way of looking at it is to say that when the eyes spend more time looking at the monitor, rather than far away, the monitor distance becomes the "normal" focusing distance. When looking at another distance, particularly far away, objects may look blurred and out of focus. A simple, yet useful standard is to stretch out your arm and have the monitor positioned at least fingertip distance away. The closer the monitor, the greater the strain.

5. Font Size: There's nothing efficient about someone leaning over their computer squinting at the screen trying to see whether a number is a 6 or an 8. Smaller font or letter size may allow you to see more information on a single screen, but it also makes the images difficult to read. In order to compensate for this, many computer users will start getting "sucked in" to the screen. In other words, what starts out as a comfortably seated user transforms into a forward leaning, bending, squinting mess with the user looking like Quasimodo.

   The solution? Simple. Set a line of alternating 6's, 8's and 9's on the screen. While in a proper seating position, make sure that you can tell the difference, without question, between the three. If not, then start increasing the font until it's at a level where you are sure of what all the numbers are. It may not allow you to have as much information on a screen, but it will allow you to see what you want to see, without having to revert to contortions.

6. Screen Color: The human eye can discern 7-8 million different colors, with many computer users determined to try every combination on their screen. While certainly colorful and vibrant, many choices are not the best for seeing the screens words and images. The best color combination of letters on background is black letters on a white background. This allows for the greatest contrast. In addition, the white background will limit the effects of glare on the screen. Now this combination may not be as sexy as purple letters on a pink background, but it is a lot easier to see.

7. Screen Size: While bigger may be said to be better, it's not necessarily better for computer screens. Getting a larger screen will definitely give you more "real estate". That is, you will be able to fit a greater amount of documents and spreadsheets on a single screen. However, the larger screen does not mean larger letters. As a matter of fact, in many cases, depending upon the type of screen, the numbers, letters and graphics may actually be smaller. And then you're back to adjusting font size. In addition, the larger screen may prevent you from having the proper monitor height. So, stop trying to get a monitor that's large enough to block out the sun. Go with one that is large enough to show your standard work documents.

8. Keyboard and Mouse Height: If your arms are too tired to pick up your drink at the bar, chances are your keyboard and mouse are not at the right height. The easiest way to determine the proper height is to sit at your computer with your arms hanging straight down. Then, without moving your elbows, bring your hands up so that they are parallel to the floor. This is the right keyboard and mouse height. If arms are well below the keyboard and mouse, you will probably need an articulating keyboard and mouse tray. This device has a space for your keyboard and mouse, and attaches directly to your desk. It has adjustments for height, distance and angle. Don't be fooled into getting one of those keyboard trays that just slide under your desk. They have no adjustment and are meant as more of a space saver than to correct your posture.

9. Contact Lenses: Contact lenses can be a means of seeing clearly and comfortably or a source of dryness and irritation for a computer user. With a higher viewing angle than paper and decreased blinking due to increased concentration, computer use can lead to contact lens discomfort. No one wants to have irritating contacts and red eyes. While all contact lenses correct vision problems, some may not be suited for the computer users. Contacts are made of differing materials, sizes and shapes. Just because a particular lens doesn't work for you doesn't mean that you can't wear contacts. It's important to understand that a computer using environment is very different from sitting at home reading a book. With the wide variety of lenses we have available to us, one of them is sure to work for you. Rewetting drops may help, but if you're using them more than twice a day, all you're doing is masking the underlying problems.

   In some cases, it may not be the contacts that are creating the red, stinging, dry eyes. It may be your contact lens solution. Sensitivity to one of the components of the solution can cause the eyes to change how they tear and result in wearing problems. If you regularly experience stinging when you first put your contact lenses on, it may be a solution reaction. Change to a different brand and change lenses, if the lenses are disposable.

10. Glasses: Whoever said "Boys don't make passes at girls who wear glasses" certainly didn't have any sense of fashion. Today, glasses are not just a method to correct your vision, but as a style statement as well. Go with the "look" you want. Whether it's conservative, invisible, freaky or funky, there's a frame for you. But there are some prescription dependent rules.

    Understand that as prescriptions get higher, so does the thickness of the lens. The same is true with the size of the frame. If you have a higher prescription, do not go with too large a frame. It will only make the lenses heavier, thicker and more unattractive. Stay with a smaller size and possibly add some color to lend a sense of style. Likewise, anti-reflection coatings can be added to the lenses to get rid of unsightly glare and reflections in the lenses. Even though you're wearing glasses, everyone should be able to see your beautiful eyes.

Dr. Glasser, nationally known for his expertise in the area of computer ergonomics, is a member of the American Academy of Optometry and is certified in Computer Eyecare through the University of California-Berkeley.