After undergoing excimer laser surgery, patients remove their glasses and the world becomes clear and bright, although they can see clearly, but not necessarily comfortably. In fact, these different symptoms have a common culprit, and that is “dry eye”. Dry eye syndrome is a condition in which the signs and symptoms of the eye are caused by a decrease in the amount and/or quality of tears. Tears contain nutrients such as vitamins and antibacterial substances such as lysozyme, which play a role in protecting and nourishing the surface of the eye. In addition, with each transient movement of our eyes (the proverbial blink), tears cover the surface of our eyes evenly, forming a thin “tear film”. Having a good and stable tear film is the guarantee of clear and comfortable vision. During excimer laser surgery, the nerves on the surface of our eyes are cut off due to the creation of the corneal flap, which decreases the perception of the surface of the eye and reduces the frequency of transient eye movements. In addition, the curvature of the cornea is changed by surgical cutting, and the tear film becomes more unstable on the surface of the eye, which can also lead to a shorter tear film rupture time and dry eye. But don’t worry too much, this kind of dry eye after refractive surgery is only temporary, usually lasting 1-6 months after surgery, and the symptoms will gradually improve and disappear through the use of artificial tears and the repair of our own eye surface after surgery. However, even without surgery, dry eye often occurs in the normal population, mainly due to external and internal factors. External causes include our environmental factors, such as high altitude, sunlight, dry, windy environment, use of heaters, hair dryers, air conditioners can increase tear volatilization to reduce eye lubrication. Or long-term wearing of corneal contact lenses, long-term use of some medications: including anti-congestants, antihistamines, diuretics, heart disease and ulcer medications, oral contraceptives, anti-anxiety medications, narcotics, and medications containing beta blockers that reduce tear production. Internal causes include some diseases of the ocular surface, such as conjunctivitis, keratitis, blepharitis and other eye diseases, as well as some immune diseases of the whole body, such as dry syndrome. The daily care of dry eye after refractive surgery includes: 1. The routine use of “artificial tears” after surgery. Artificial tears are a substitute that imitates the composition of human tears. It is a kind of eye drops, can play a role in moisturizing the eyes. There are many good artificial tears on the market, such as polyethylene glycol eye drops (Siren), sodium vitreous acid eye drops (Hailu or Ally), sodium hydroxymethylcellulose eye drops (Bright Vision) and so on. Generally, you can try several artificial tears, and then choose the one that you feel most comfortable after the point with the best effect. 2, healthy lifestyle habits. Including drinking water: drinking more water is obviously beneficial to dry eye, if the body is dehydrated, the eyes are also bound to be dehydrated. Pay attention to rest and rest, especially control the use of computers, TV, cell phones and other electronic products time. Eat more vegetables and fruits in the diet, and less spicy and stimulating food. 3, improve the environment. In a dry environment, air-conditioned environment, too hot, too cold environment, the humidity in the air will drop. If possible, try to avoid this environment, or use a humidifier. The flow of air, such as wind, will also accelerate the volatilization of tears, and should avoid fans blowing directly on the face. 4. Actively treat eye diseases, such as blepharitis, conjunctivitis, keratitis, etc. It is believed that after refractive surgery, maintaining a positive and optimistic attitude, regular review according to the doctor’s requirements, standardized use of artificial tears, and adopting a healthy lifestyle, everyone can fully enjoy both a clear and bright and comfortable life after taking off glasses.