I stare at a computer for entirely too many hours a day ó more than Iíd care to think about ó and by the end of the week, I feel it. At least, my eyes do.

Eye strain from staring at a computer is so common it has its own name: computer vision syndrome. And itís pretty widespread, though estimates of its prevalence vary. The symptoms will probably sound familiar: blurry vision, headaches, dry eyes, watery eyes, and tired eyes.

For most people these symptoms are temporary, and if you stop using a computer for a while, theyíll go away. The bad news is that these symptoms can occur if youíre looking at a computer for two hours. If youíre like me, you look at computers a lot more than that.

Computers are harder on the eyes than printed pages in part because we blink less. Our blink rate drops by a third when weíre reading on screens, leaving our eyes dry, according to the University of Iowa. There are some other reasons, too, the American Optometric Association says: the contrast between characters isnít as strong on a screen as in a book, and letters are less precisely rendered. All of these things make the eyes work harder, leaving them tired. Staring at the screen from a less-than-ideal angle only exacerbates the discomfort. Ideally, you should be looking slightly down at your screen ó at a 15 to 20 degree angle ó and it should be placed about 20 to 28 inches from your eyes.

It helps to take rest breaks. Every 20 minutes youíre on the computer, take 20 seconds to stare at something 20 feet away ó optometrists call this the 20-20-20 rule. After two hours of continuous computer use, take 15 minutes away from the screen ó to rest your eyes. Some people who donít ordinarily wear glasses may also benefit from getting computer-specific specs. These glasses reduce glare and increase contrast, so your eyes donít have to work as hard when youíre working with spreadsheets or writing fire tweets. Working at a computer also gets more difficult as you age and your eyes are less flexible. Contact lens wearers may deal with more dryness and blurriness, because you already blink less while wearing contacts. I often wear my glasses instead of my contacts ó I find that helps. I also use lubricating eye drops, so my eyes donít feel as parched.

If youíre having trouble after a long day of staring at the computer, it might be worth saying hello to your eye doctor ó people with undiagnosed alterations in their vision are more at risk for eye strain. But the good news is that your vision is probably going to be fine in the long run. Just try to be kind to your eyes.