Research by the Department of Optics at the University of California shows that people who use computers for long periods of time commonly suffer from VDTs dry eye, which means that they are prone to dry eyes, red eyes and fatigue, and that 10 million people in the United States are now affected by it. Experts predict that with the popularity of computers, the number of people with dry eye in China will rise at a rate of 10% per year in the next five years. Vision experts believe that this phenomenon is closely related to the lack of blinking when using computers. This is because when people look at the fluorescent screen, the number of blinks of the eyes is invariably reduced, from 20-25 blinks per minute to 5-10, thus reducing the secretion of the intraocular lubricant – tears – and at the same time the eye is exposed to the air for a long time, making The water evaporates too quickly, causing dry eyes and discomfort, which can easily cause dry eyes in the long run, and can even damage the cornea in serious cases. In addition, the computer fluorescent screen consists of small fluorescent dots, the eye must constantly adjust the focus to ensure clear vision, too long, the eye muscle will be too fatigue. Computer fluorescent screen electromagnetic waves, ultraviolet rays, radiation, blinding colors and infrared rays can also stimulate the eyes, causing eye dryness, fatigue, double vision, blurred vision and even head and neck pain and other problems. Some computer operators often frequent drops of eye drops, in fact, eye drops should not be used indiscriminately, there are misguided people often use Japanese eye drops, in fact, containing preservatives are not suitable for dry eye disease; especially eye drops containing antibiotics or hormones, some eye drops may even aggravate the symptoms of dry eyes. Doctors recommend the appropriate use of preservative-free artificial tear products to alleviate and eliminate the eye discomfort caused by VDTs. This is because artificial tears are safer and can properly replenish and retain tears. For example, the German Hailu and the American Bright Vision eye drops do not contain preservatives and can retain tears for a long time.