According to a recent study done in Japan, people who spend long hours looking at a computer screen experience the same changes to their tear fluid as do those who are suffering from chronic dry eye. MUC5AC is a protein that is secreted by cells found in the upper eyelids. This is part of the “tear film” that functions by keeping the eyes moist. The subjects in the study who were on computers the most had levels of MUC5AC that resembled people who had been diagnosed with dry eye.
One of the authors of the study, Dr. Yuichi Uchino, said that eye strain and the resulting levels of MUC5AC are important symptoms that ophthalmologists look for. An ophthalmologist himself, Dr. Uchino works at Tokyo’s Keio University School of Medicine. Part of the problem is that staring at a computer screen causes users to blink less compared to when they are reading a book.
The fact that eyelids are opened wider when looking at computer screens than during any other daily task only exacerbates this issue. Dr. Uchino adds that extra surface exposure and sporadic blinking lends to an acceleration of the evaporation of tears, which in turn is associated with chronic dry eye. Both the disease and the symptoms can be easily managed by using prescription or over the counter eye drops.
According to the report, past studies have shown that as many as 5 million people in the U.S. aged 50 years and over suffer from chronic dry eye. Tens of millions of Japanese people, particularly those who work on computers, say that they experience various symptoms of dry eyes.
The researchers tested both eyes of 96 subjects, two-thirds of which were men and all of whom were office workers. The team measured the participants’ tears to find how much of the total proteins present were MUC5AC. The subjects also completed questionnaires regarding work hours and eye problem symptoms.
The subjects diagnosed with chronic dry eye were 14 percent of the women and 7 percent of the men. These people said that they experienced symptoms such as blurred vision, burning sensations and irritation. All of the diagnosed subjects had either poor quantity or quality of tear film.
Generally, subjects who worked a little over eight hours per day had an average of 6.8 nanograms of MUC5AC per each milligram (ng/mg) of protein in each eye. Those who worked well over seven hours a day averaged 5.9 ng/mg, while people who worked less than five hours a day at a computer had 9.6 ng/mg of MUC5AC. On average, people who had been diagnosed with chronic dry eyes had 3.5 ng/mg and those who had not been diagnosed had 8.2 ng/mg.
Dr. Yuichi Hori, an ophthalmologist who was not part of the study, said that mucins, like MUC5AC, are a very important part of the tear film. They function by holding water on the surface of the eye, thereby playing a major role in the overall maintenance of the ocular surfaces, particularly the tear film. Dr. Hori is the chair of the ophthalmology department at Tokyo’s Toho University Omori Medical Center.
Dr. Hori advises workers who suffer from dry eye symptoms and ocular fatigue to consciously make attempts to blink more often. Dr. Hori also encourages the use of artificial tears. He adds that if symptoms persist, individuals should seek medical advice.
Dr. Uchino points out that previous research has shown that workers who experience dry eye symptoms are less productive and tend toward depression. He said that there are some simple ways of mitigating dry eye problems. By putting the screen lower and tilting it upward, the ocular surface that is exposed for long periods of time is decreased. It is also helpful to use a humidifier and to avoid sitting in the direct path of the air coming from a fan or an air conditioner. Since it now seems clear that long hours at the computer can change people’s eyes, at least there are some easy ways to combat the changes.
By Stacy Lamy