Dry eye, or corneoconjunctival dryness, is a general term for a variety of disorders characterized by abnormal tear film stability due to abnormal tear quality and quantity or kinetics from any cause, accompanied by ocular discomfort and resulting in ocular surface tissue lesions. It includes dry eye, dry eye disease, and dry eye syndrome. Dry eye syndrome is a condition in which the symptoms of dry eye are transient and return to normal after rest or brief application of artificial tears, and there are no signs of dry eye, especially no damage to the ocular surface, and no local or systemic causes of dry eye. Those who have both symptoms and signs are called dry eye disease, and those who have combined systemic immune diseases are dry eye syndrome. I. Etiology and classification: The etiology of dry eye is numerous, the pathological process is complex, and the connection or causal relationship between the factors is not yet fully understood. Dry eye can be divided into insufficient tear production type and evaporation overpowering type. Clinical manifestations: The most common symptoms of dry eye are eye fatigue, foreign body sensation, dryness, other symptoms include burning sensation, eye swelling, eye pain, photophobia, eye redness, etc. If you have symptoms of appeal, you should seek medical attention as soon as possible. Signs of dry eye include dilated bulbar conjunctival vessels, loss of luster of the bulbar conjunctiva, thickening and edema, folds, narrowing or interruption of tear rivers, sometimes yellowish mucous filamentous secretions seen in the inferior fornix, punctate loss of corneal epithelium to varying degrees in the lid fissure area, progression of the disease, filiform keratitis, and in advanced stages, corneal ulceration, corneal thinning, perforation, and occasionally secondary bacterial infection. After the formation of corneal scar, it seriously affects the vision. Third, treatment: first of all, it should be clear which type or which type is the main in order to take targeted measures, in addition, dry eye disease is a chronic disease, requiring long-term treatment, patients must establish the confidence to adhere to treatment. 1, should eliminate the causative factors, should try to avoid prolonged use of computers, less exposure to air conditioning machines smoke environment, etc.. 2, local treatment: mainly tear supplementation and relief of symptoms. Commonly used drugs for artificial tears, for serious patients should try to use artificial tears without preservatives. Wear hydrophilic soft corneal contact lenses with artificial tears. Tear punctal plugs are helpful in the treatment of moderate to severe dry eyes and can temporarily or permanently reduce tear drainage. Temporary tear plugs should be tried before permanent tear plugs are inserted, and permanent tear plugs should be placed only after there is no tear drainage. In more severe cases, permanent lacrimal punctal closure may be considered. For patients with lid entropion and ectropion, lid margin suturing may be considered. 3. Systemic medication: Oral administration of Bystolic helps to relieve dry eyes and dry mouth symptoms. 4. Etiological treatment: mainly the application of steroids and immunosuppressive drugs.