Medically speaking, dry eye refers to the inability of the eye to produce enough teardrops or teardrops evaporating too quickly. A special protein called MUC5AC makes up the normal mucus layer, or tear film, which is what keeps the eyes moist. But one study found that participants who spent most of their time sitting in front of a computer screen had levels of MUC5AC protein close to those of people diagnosed with dry eye. The team tested the teardrops of 96 Japanese office workers’ eyes and measured the amount of MUC5AC protein in the tears. Those participants who had to work in front of a computer screen filled out questionnaires about their working hours and whether they had any eye problems. Dr. Yuichi Uchino, one of the authors of the study, said that people who stare at screens usually open their eyelids wider while working, and that exposing more of the eye surface and rarely blinking also accelerates the evaporation of tears, which can cause them to suffer from dry eye. He added, “Staring at a computer screen reduces the number of times we blink compared to the process of reading a book.” The team found that participants who worked in front of a computer screen for more than seven hours a day had an average of 5.9 ng/mg of MUC5AC protein in their tear film, compared to 9.6 ng/mg for those who faced a computer screen for less than five hours a day. Normal people had 8.2 ng/mg. Office workers who are concerned about developing dry eye can make some simple changes to reduce the risk of the disease. For example, placing the computer screen at a lower height and tilting it upward can reduce the amount of exposed visual surface. You can also place a humidifier in the office or avoid being blown directly by the air conditioning, etc.