Dry eyes and technology: What you need to know to protect your vision

(CBS News) Do your eyes feel dry? You're not alone. Millions of Americans suffer from dry eyes, and experts say computers and smartphones are making the problem worse.

That's because when staring at those devices, you may be blinking somewhere around 50 percent less often that you do when looking at other everyday things, says Dr. Christopher Starr, an associate professor of ophthalmology at Weill Cornell Medical College. He explained on "CBS This Morning," "Normally, we blink about 20 times per minute. It can drop to eight or 10 times a minute. And when you're not blinking, the tears that are on your ocular surface just evaporate. You're not distributing new, healthy, clean tears across the ocular surface."

Another thing that can contribute to the dry-eye feeling is the lack of oil being distributed to the eye via your eyelid. "When we blink, we push out a little bit of oil," Starr said. "It's critical for healthy tear film. ... When you blink, you put out a little oil with each blink. So if you're not blinking, you're not getting the oil, your tears are evaporating and over the hours of a long workday that leads to significant dry eye."

Symptoms of dry eye include grittiness, a sandy feeling, a foreign body sensation, burning, redness, and sometimes tearing, and blurry vision. Star added, "Vision can (also) fluctuate, so if you have clear vision in the morning, blurry vision at the end of the day, it's often in relation to this."

To reduce dry eye symptoms, Starr recommended the 20/20/20 rule: "Every 20 minutes you're on the computer, take a break, look away at a distant object that's 20 feet away or further for 20 seconds or more. You can put a little sticker on your computer or a bottle of artificial tears to remind you to do that periodically."

Watch Starr's full interview above.