In the Blink of an Eye

You've been staring at your computer screen for hours. Now your eyes are as dry as sandpaper. Coincidence?

Not remotely. The muscles you use to squint are the same ones used to blink. And most of us frequently squint at computer screens, consciously or not. When you're squinting, you're not blinking normally, so your eyes aren't getting the lubrication they need. This won't cause any long-lasting damage, but it's uncomfortable.

Even slightly squinting at a computer can cause problems. According to a recent study, just a tiny narrowing of the eye cut the number of blinks in half, from 15 down to 7.5 times a minute. Full squints (eyes halfway closed) cut blinking to only 4 times a minute. When blinks are that few and far between, it's no wonder eyes wind up irritated and achy.

You may be able to solve the problem with a few easy steps. First, reduce the glare on your computer screen -- change the lighting, reposition your computer to avoid window reflections, or use an antiglare screen filter. Next, adjust the brightness and contrast levels on your computer monitor to sharpen readability. Finally, take a break -- it's good for your spine and wrists as well as your eyes.

Reference
Blink rate decreases with eyelid squint. Sheedy, J. E., Gowrisankaran, S., Hayes, J. R., Optometry and Vision Science 2005 Oct;82(10):905-911.