With summer approaching, more and more students are having myopic eye surgery. Among them, many students and parents have reported itchy eyes, bloodshot eyes, and occasional blurred vision after surgery, which will return when they blink. The cause of surgical flap making leading to decreased tear film stability The etiology of operative dry eye is mainly due to LASIK surgical flap making and the use of eye medication in the short term after surgery, which reduces the transient vision of patients and decreases the stability of the tear film. It is understood that LASIK surgery is currently performed in three main steps. First, a circular flap (corneal flap) with a tip is cut in the cornea in front of the pupil using a lamellar knife or femtosecond laser. The flap is then turned over to expose the middle layer of the cornea (stroma) and laser irradiation is used to vaporize the stromal layer for shaping to correct the refractive error. Finally, the flap is reset. Due to the reduction of the stroma after surgery, although the flap is turned back to its original shape, its curvature has changed and the flap area will be flatter compared to before. Tears do not adhere as easily to the cornea. The change in curvature affects the attachment of the tear film.” Li Fusheng said. In addition to reducing tear attachment, creating a corneal flap also cuts the superficial corneal stromal nerve. When the corneal nerve is severed, the patient’s perception decreases and the number of blinks decreases. This is because each blink causes the tear film to coat the corneal surface evenly. Therefore, it also tends to cause dry eyes. In addition, causes of operative-derived ophthalmia include patients who must use antibiotic and hormonal eye drops after surgery to prevent surgical wound infection and reduce wound healing reactions, but prolonged use of eye drops can alter the balance of the conjunctival sac microenvironment, causing patients to secrete fewer tears and causing dry eyes. “The tear film on the corneal surface itself acts as a thin lens, and dry eyes are bound to affect vision. So, usually blink to make the tear film coating evenly, vision often improves.” Artificial tears can relieve dry eyes If post-operative dry eyes are not treated promptly, over time, dry spots will appear on the corneal epithelium, eventually triggering corneal inflammation and affecting post-operative results. Therefore, postoperative dry eyes need to be treated promptly. Usually, patients can choose artificial tears (sodium vitreous acid) within 1-3 months after surgery, and 2-4 times a day drops are sufficient. A small number of patients already have varying degrees of dry eyes before surgery due to long-term contact lens wear before surgery, so the use of artificial tears (sodium vitrate) after surgery may take longer. After treatment, the vast majority of patients’ dry eyes will gradually ease and disappear within six months, and the medication can be discontinued. However, a small number of patients can still order a little artificial tear solution to relieve computer terminal syndrome when their eyes are dry due to long-term computer use, even after their dry eyes have healed. The commonly used artificial tears include sodium vitreous acid, polyethylene glycol, polyvinyl alcohol and hydroxyglycolic anhydride. The core of choosing artificial tears is to be as preservative-free as possible. Therefore, you can look closely at the formulation of artificial tears. If there are “BAK”, “Polyquad” or “other excipients” in the instructions of the solution, you should choose carefully.