Computers, television, and other digital devices can cause dry eyes because using these devices affects how we blink.
Blinking is important because, with every blink, your eyelids spread a fresh layer of tears across the surface of your eyes to keep them moist, comfortable, and healthy.
Unfortunately, people typically don't blink their eyes normally when using a computer or other digital devices or simply watching television intently.
Specifically, computer use affects both blink rate (how frequently we blink) and blink completeness (whether the eyelids close completely during a blink).
We normally blink about 10 to 15 times per minute. But studies show when people are working at a computer, they tend to blink less than half that often. Also, computer use tends to cause more incomplete blinks, so the tear film is not spread across the entire cornea.
This decrease in blink rate and increase in the percentage of incomplete blinks increases the risk of dry eye symptoms during computer use.
A good way to re-establish proper blinking when using a computer or other digital devices is to take a break from looking at the screen at least every 20 minutes. Direct your gaze across the room (at least 20 feet away) during these breaks and blink fully and frequently. Do this for at least 20 seconds. (Eye care providers call this the "20-20-20 rule.")
Taking these short breaks routinely can significantly help you avoid dry eyes and computer eye strain.