Do your eyes often feel dry, foreign body sensation, pain, photophobia, vision fatigue, or blurred for some time after your refractive surgery? If so, you may be suffering from “dry eye”. Dry eye is one of the common complications after excimer laser keratomileusis surgery, which often reduces the satisfaction of surgical results to varying degrees. According to the survey, the incidence of dry eye in the early postoperative period (within 6 months) is about 35%; by 1 year after surgery, the rates of dry eye are: PRK0,9%, LSAEK0,8%, and LASIK6,0%. Overall, lamellar keratomileusis (LASIK) had a higher incidence and longer duration of dry eye than superficial refractive surgery (PRK, LASEK, Epi-LASIK). The main causes of dry eye associated with keratomileusis: 1, the impact of preoperative dry eye risk factors Up to 38% of myopic patients have dry eye symptoms before surgery, and are more likely to have severe dry eye after LASIK, and having dry eye before surgery increases the risk of complications during and after LASIK, including corneal epithelial defects, epithelial endothelial growth, infection and refractive regression. 2. The effect of surgical factors on dry eye Multiple and excessive use of surface anesthetics can be toxic to corneal epithelium and stromal cells, causing epithelial defects, diffuse lamellar keratitis and epithelial endothelial growth. The incidence of dry eye 1~2 weeks after LASIK is as high as 69%~85%. The microkeratome or femtosecond laser used in LASIK surgery cuts the sensory plexus within the anterior corneal stroma, and the corneal perception is reduced in the early postoperative period (3~6 months), thus leading to a decrease in the number of transients, increased tear evaporation, and changes in corneal morphology affecting tear film attachment and stability. 3, postoperative causes of dry eye Most of the glucocorticoids and antibiotic eye drops used routinely after surgery contain preservatives, which can produce toxic effects on the corneal epithelium in the postoperative dry eye state. Wearing contact lenses, eye surface cell damage, tear reduction or composition changes can also lead to dry eye. 4, other influencing factors: patients wearing contact lenses for a long time before surgery, older age and living in a dry climate, long-term computer work, etc. The main characteristics of dry eye after keratoconus surgery: 1 to 6 months after surgery (individual 1 year or more), there are often symptoms such as dry eyes, easy fatigue and fluctuating vision, especially after excessive eye use is more serious. These symptoms may gradually decrease with prolonged postoperative time; mild conjunctival congestion, diffuse fine dot staining of the cornea or corneal flap below; objective examination indicators: abnormal tear secretion test and tear film rupture time, gradually recovering to the preoperative degree by 3~6 months postoperatively. Treatment of dry eye after keratoconus surgery: 1, eye local point various artificial tears, including sodium hyaluronate, hydroxypropyl methylcellulose, carboxymethyl cellulose na, etc., because preservatives can cause or aggravate the damage to the surface of the eye, need long-term use when it is recommended to use artificial tears without preservatives. 2, tear duct plug plug closure: by partially closing the tear drainage pipe, in order to increase the surface of the eye to play a role in lubrication of natural tears. Blocking the lacrimal duct is like plugging the “sewer” where the tears flow out, which can preserve the natural tear fluid in the eye to the maximum extent. For dry eyes caused by surgery alone, temporary tear duct plugs that are biodegradable for six months are available. Prevention of dry eye after keratoconus surgery: 1. For patients with dry eye before surgery, treatment should be started before surgery, such as hot compresses and use of artificial tears, after the corneal epithelium has been repaired. 2.Avoid prolonged exposure of the eye in the air. When watching TV, computer or reading, do not stare for a long time, but keep blinking to let the tears on the eyelids lubricate the eye. 3, to change the habit of using the eyes continuously for a long time, read books, newspapers, TV, computers or do meticulous work, every hour or so, to rest 5 to 10 minutes, or close the eyes to rest, or look into the distance. 4.Live a regular life, go to bed early and get up early, don’t stay up late, and ensure sufficient sleep to prevent excessive eye fatigue. 5.Don’t get eye shadow powder and mascara used in makeup into your eyes to avoid irritating effects on your eyes. 6, very personal residual farsightedness, myopia, astigmatism, etc., to wear the right number of glasses to correct, but should not wear contact lenses, if you have to wear contact lenses, the time should not be too long. 7, if the occurrence of eye dryness and discomfort, see things blurred, to the hospital for examination and treatment. Under the guidance of the doctor for treatment, do not use eye drops indiscriminately to point eyes, so as not to aggravate the condition.