I. Dry eye and tear film Dry eye (also known as corneoconjunctival dryness) is a general term for a variety of disorders characterized by abnormal tear quality or quantity, or abnormal kinetics resulting in decreased tear film stability, with ocular discomfort, and/or ocular surface tissue lesions, from any cause. Dry eye is one of the common ocular surface disorders. What is the tear film? The normal ocular surface is covered with a tear film, which is divided into three layers: lipid layer, aqueous humor layer and mucin layer from outside to inside. As shown in the figure: II. Common causes Any cause of lesions of the lacrimal gland, the ocular surface (cornea, conjunctiva, lid gland), eyelids, and the nerves that innervate or feel these tissues can cause a decrease in the stability of the tear film, leading to dry eye. For example: 1. congenital: such as Riley-Day syndrome, congenital atelectasis, lacrimal gland deficiency, etc.; 2. secondary: primary or secondary dry eye syndrome related to autoimmunity; dry eye caused by eye infection, trauma, medication, surgery, endocrine disorders, etc. (e.g. inflammation, surgery, trauma or infection of the lacrimal gland, paracrine gland, lid gland and other glands can cause reduced tear secretion and (decrease in the stability of the tear film). In addition, long-term use of certain medications or cosmetics, wearing contact lenses, excessive eye use and use of electronic devices, cold, dry or polluted living and working environments, radiation, long-term use of various eye drops, and long-term use of systemic medications such as anti-hypertensives and antidepressants are all common causes of dry eye. The most common symptoms of dry eye patients are dry eyes (just like a machine lacking lubricant, feeling dry eyes and not moving much); photophobia (reluctance to open eyes, easy to flow tears, especially under strong light, oil fumes or air conditioning environment is more likely to occur), in addition, dry eye patients will also be more likely than normal people to visual fatigue, vision can not last, some will be accompanied by eye redness, vision In addition, patients with dry eyes are more likely than normal to experience visual fatigue, unsustainable vision, and in some cases, redness, decreased vision, foreign body sensation, burning sensation, eye pain and increased discharge. Severe dry eyes can lead to persistent corneal epithelial detachment, corneal ulceration, infection or even perforation, and even blindness. If the above symptoms are present, a careful medical history should be taken to find the possible causes of dry eye. For severe dry eyes, we should ask if there are systemic symptoms such as dry mouth and joint pain, and give corresponding examination to exclude dry syndrome. Treatment The treatment of dry eye includes two aspects: 1. Treatment of the cause: The cause or possible cause of dry eye should be clarified in order to take targeted measures. For example, if the dry eye is caused by excessive tear evaporation due to eyelid abnormalities, corresponding eyelid reconstruction should be given; if the dry eye is caused by lid gland dysfunction, corresponding medication or physical therapy should be given. (1) Pharmacological treatment: such as artificial tear drops to keep the eye surface moist and relieve dry eye symptoms, which is one of the main measures to treat dry eye; local and systemic anti-inflammatory and immunosuppressant use. (2) Surgical treatment: such as tear dots closure. In addition, various triggers that can aggravate dry eye symptoms should be avoided as much as possible. V. Suggestions Because people do not know enough about dry eye, they tend to buy eye drops from pharmacies when they have eye discomfort. As a reminder, eye drops generally contain preservatives, which can damage eye surface tissues and cause pharmacogenic keratitis if used for a long time without medical advice or frequently replaced, thus aggravating the symptoms of dry eye patients and affecting their life and work. Therefore, if you have eye symptoms, it is recommended that you do not abuse eye medication and go to the hospital to see a professional doctor for a clear diagnosis so as not to delay diagnosis and treatment.