"Our society has become so visual, many of us use our eyes for practically everything we do during our waking hours!"
"We're guessing that many computer users would agree that their eyes are being overused and abused rather than exercised in some healthful way."
"It seems clear that we may need to start taking better care of our eyes as well as our bodies"
"For one thing -- we can try to remember to take plenty of breaks from computer-gazing and other near-point work."
"Take "eye breaks" by looking off into the distance and focusing on many different targets"
More at http://www.vision3d.com/exercise.html