In an effort to isolate the causes of eye strain, which is one of several major symptoms of “dry eye” disease, researchers analyzed the tear fluid of office workers who spend long periods of time peering at computer screens. They found that those who spent the most time looking at their monitors had the least amount of the protein (known as MUC5AC) that is secreted by cells in the upper eyelid to create the mucus layer in tears (“tear film”) that keeps the eye moist. In fact, the workers who spent the most time watching their computer screens had MUC5AC levels that approached the levels seen with individuals diagnosed with dry eye. Treatment with artificial tears can help.
P.S. Because they tend to blink less often than usual and open their eyes wider, people in front of computer screens are likely to be more susceptible to ocular fatigue and dry eye symptoms.