The etiology of dry eye syndrome is attributed to: 1, the elderly hormone level changes significantly and the incidence of various systemic diseases increase and lead to reduced tear secretion, in addition to bacterial conjunctivitis and some autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus will cause secondary Sjǒgren syndrome, tear lysozyme level decreases significantly, can affect the secretion of tears; 2, long hours of video screen terminal work, games, long-term staff in sandy and polluted areas, drivers who drive for a long time and need to concentrate will also experience reduced transients and rapid tear evaporation leading to dry eye; 3, damage to the cup cells of the conjunctiva, Henle’s crypt, Manz’s gland and non-cup mucus secreting cells of the lacrimal gland can also cause dry eye; 4, the eye surface is not smooth after ocular surface surgery making The incomplete tear film and the long-term use of preservative-containing ophthalmic drugs after surgery can change the kinetics of tears and cause tear film rupture, resulting in dryness of the cornea; 5. The increase in the number of children with paraphthalmia, the prolonged exposure of children to video screen terminals, allergic ocular surface diseases that damage the conjunctival cupped cells, reduce tear secretion, and reduce lipids and mucus proteins also lead to dry eye. It is important to understand the etiology and disease characteristics of dry eye to prevent and treat dry eye.