Computer vision syndrome

Overview
Computer vision syndrome (CVS) is a temporary condition resulting from focusing the eyes on a computer display for protracted, uninterrupted periods of time. Some symptoms of CVS include headaches, blurred vision, neck pain, fatigue, eye strain, dry, irritated eyes, and difficulty refocusing the eyes. These symptoms can be further aggravated by improper lighting conditions (ie. bright overhead lighting or glare) or air moving past the eyes (ie. overhead vents). CVS has not been proven to cause any permanent damage to the eye.

One may be able to mitigate the risk of CVS by adhering to the "20-20-20 rule": every 20 minutes, focus the eyes on an object 20  feet (6 meters) away for 20  seconds. Also, the use of over-the-counter artificial tear solutions and computer glasses can reduce the effects of CVS.