Eyes also get a workout focusing and refocusing as they glance back and forth from a document to the screen. Glare from screens and bright office lighting are also issues. Computers should be illuminated from the side, not from directly in front or back, says Kilber. Then there's the dry-eye problem. People normally blink 14 times per minute, which helps lubricate eyes.
Computer users blink five times per minute.
Jan Paschal, a copy editor for Reuters, says she spends at least seven hours a day at her computer. I've learned to be very protective of my eyes. She uses an eye wash four times a day and takes visual timeouts. And optometrist Dr. Dennis Ruskin from Toronto has developed a reference manual on CVS and a software program that tells you when to take breaks.