Dry eye is keratoconjunctivitis sicca, which is an inflammatory reaction that conjunctiva and cornea can't be wetted. The normal ocular surface is covered with a tear film, and a stable tear film is the basis for maintaining the health of the ocular surface. Tears have the functions of disinfection and sterilization, as well as lubrication of eyeball and maintenance of corneal refractive system. Blinking is a protective nerve reflex, which can make tears evenly distributed on the surface of cornea and conjunctiva to keep the eyeball moist but not dry. Normal people blink about 20 times a minute. If you open your eyes for a long time and stare at the rapidly changing screen, the number of blinks will often be reduced to four or five times per minute, and the symptoms of dry and sour eyes will appear. If there is too little tear secretion, the cornea will never get moist, the whole eyeball will be dry and dull, and the corneal epithelium will be keratinized and form obvious scars. You can't see clearly when you see things, your eyes will feel burning and foreign body sensation, and visual fatigue and eye grinding pain will form dry eye syndrome. It causes dry eyes, easy fatigue, sticky secretions, foreign body sensation, fear of wind blowing, temporary blurred vision and other symptoms. Seriously, it may cause redness, congestion, keratinization and silky stickiness on the cornea, as well as long-term lesions of the cornea and conjunctiva, thus affecting vision. Preventive measures for dry eye: blink more at ordinary times, and be careful not to stare at the computer and TV for a long time. At the same time, pay attention to eye hygiene and don't rub it with your hands.