If you're reading this online, chances are you are straining your eyes and probably your neck and back as well. If you're holding the paper while reading this, your turn will come later when you check your e-mail.

According to Dr. Marc Grossman, O.D., more than 50 percent of computer users experience eye strain, headaches and blurred vision from starring at the computer screen for hours at a time.

There is a condition called CVS, Computer Vision Syndrome, where one's sight is light-sensitive with blurred vision. The size of words often changes. All this is due to improper use of the computer monitor.

It's not just eye strain, either. Computer users often complain of back, neck and hand aches, sometimes leading to carpal tunnel syndrome.

The best prevention to all this is frequent breaks, good lighting and proper posture.

You should sit upright in an adjustable and comfortable chair with your feet flat on the floor. Your shoulders should be relaxed and your monitor should be about 16-20 inches in front of you, according to folks at the Mayo Clinic. To reduce fatigue, tap the keyboard gently with your forearms parallel to the floor.

During your breaks, do some stretching exercises. Relax your neck and shoulders and close your eyes. Take a deep breath. When you exhale, drop your chin to your chest and gently roll your head clockwise as you inhale. Do it slowly, get the kinks out and reverse direction when done. Be conscious of your breathing and keep relaxed. Do these rolls in each direction a couple of times.

Stand and brace your hands over your head to release shoulder tension.

Exercising your eyes will help to deduce focusing fatigue. Look away from your monitor every half hour or so and focus on something across the room or out the window. Look at it for 10-15 seconds. Then look back at something close and stare at it for the same time. Do this 10 times.

Studies show that computer users blink only 20 percent as frequently as they normally do. This dries the eyes, causing blurred vision, irritation and fatigue. So make a conscious effort to blink when computing.

Our ancestors used to live outdoors, always watching the horizon in search of the food they hunted. We on the other hand, live indoors and stare at our computer monitors. It's not the way we were meant to live and it's not healthy.

One thing we can do is change from the old cathode ray tube-type monitors to the newer flat-panel LCDs, which are easier on the eyes. The CRTs have flicker, which contribute to eye strain. If you have one of those, go into the monitor settings and change the refresh rate to at least 70 Hz. LCDs have no flicker or settings to change.

When shopping for the flat panel models get one with a dot pitch of .28 or lower and be at least 19 inch diagonally in size. They will have a sharper image than those with a higher dot pitch, which are often cheaper. So -- and there is the caveat -- with monitors, cheaper is not always the best choice.

Bad lighting has an ill effect on our eyes. Try to have room lights and windows either above or to the sides of your computer. Try to minimize glare. If the light source is behind the monitors, you will be looking at it; if behind you, you'll see its reflection. The display should not be a source of light but only as bright as the room you're in.

Take a look a white background on a Web page. If it's on the dull side, brighten it a bit, but not too much.

Adjustments can be made not only from the buttons on the display, but from the software as well. You can change setting for brightness and contrast, along with gamma, saturation and vibrance in most cases. Play with it to find a comfortable setting. You can always revert back to the default setting should you find you over adjusted it.

In most computers, look where you change the resolution, most of the time by right-clicking on your desktop and depending on your version of Windows, either go to Settings, or Personalize and look for Color Management from there. You can also calibrate your display settings in there.

The Institute of Occupational Safety and Health says eye strain can not only cause fatigue, decreased productivity and CVS, but can lead to glaucoma.

The most important thing to do according to our optometrist, Dr. Elliott Brass, is to get annual eye exams and have proper eyewear. This is especially important if you work constantly in front of a computer. I wear trifocal progressive glasses. The midsection of the lens is for my computer vision and helps immensely. There are also dedicated computer glasses that you can get.

Take breaks, even if they're at your desk. Stand and stretch, blink, stare out a window, roll your head. It all helps.

 Arthur Glazer is a freelance writer and computer technician in Gainesville. His column appears biweekly. Arthur welcomes your computer questions and ideas for future columns