The main reason for people to blink is to protect the eye itself from external damage by blinking, especially when there are foreign objects close to the eye, people will instinctively form a blinking reflex, with the eyelids to block the direct damage to the eye of external objects. In addition, blinking can make the eye surface paved with tears, the process of blinking is the tear secretion in the cornea paved process, only through the blinking of tears can make the tears evenly distributed on the surface of the cornea, so that the cornea does not produce a lack of water, dry. Some patients may form exposure keratitis due to incomplete closure of the eyes when closing, or muscle spasm without the ability to blink, which is due to the lack of tear water dryness of the cornea. Therefore, the main function of blinking is to protect the eyeball and moisturize the cornea so that the cornea does not dry out or develop lesions.