A, suitable for laser surgery: age between 18-50 years old, myopia in 200-300 degrees, farsightedness 100-1000 degrees, astigmatism within 500 degrees; the last two years refractive error stability within 100 degrees, rk more than two years after surgery; health, no other eye disease patients, can do excimer laser surgery. Second, not suitable for surgery: 1, glaucoma: laser treatment requires a period of hormonal eye drops, a small number of patients can appear hormonal IOP elevation, after stopping the drug will soon recover, but the original glaucoma sufferers are not good. 2, corneal disease: keratitis, corneal endothelial degeneration, garden cone cornea, etc.. Surgery can lead to the spread of inflammation when there is acute inflammation in the eye, and corneal degeneration and other diseases are not suitable for surgery. 3, fundus lesions: those who have suffered from retinal detachment, macular hemorrhage and other diseases are not suitable for lasik surgery, but can choose prk surgery. 4, systemic connective tissue diseases and autoimmune diseases patients are not suitable for surgery.