Myopia is mainly due to the long anterior and posterior diameter of the eyeball or the bulging surface of the eyeball, and the external light cannot be accurately focused on the retina. Therefore, myopia surgery is to use excimer laser to cut the corneal stroma layer under the corneal flap, so as to reduce the corneal curvature in the pupil area and focus the external light on the retina accurately, and finally achieve the purpose of correcting myopia.