LASIK surgery mainly includes microkeratome flap LASIK and femtosecond laser flap LASIK two categories, is currently the most safe and effective surgical methods to correct myopia, its surgical indications are: 1, the patient himself has the desire to remove glasses through surgery, the expectations of the surgical results are reasonable. 2, age: generally 18 years of age or older (except for refractive error or other special circumstances). 3.Stability of refraction: The refraction is relatively stable in the past 2 years, and the annual increase of refraction is not more than 50 degrees. 4.The range of refraction: myopia generally does not exceed 1500 degrees, astigmatism generally does not exceed 600 degrees. 5. Patients with refractive error or large astigmatism who have inconsistent refractive error in both eyes. 6, Corneal thickness: generally greater than 450 mm. 7, Eye examination without active, organic lesions; or original external eye or ocular surface disease (blepharitis, dry eye, allergy) has been controlled. 8.Healthy, or pre-existing connective tissue disease or autoimmune disease that has been satisfactorily controlled. 9, Re-operators: LASIK: 3~6 months interval, preferably more than 1 year; PRK: preferably more than 1 year interval; RK: preferably more than 2 years interval. 10, residual refractive error after corneal transplantation: should be more than 1 year after surgery, six months after removal of sutures refractive stability. 11, psychological factors: the patient himself has a healthy psychological state, can fully understand and can accept the possible complications of surgery.