Myopia is caused by the anterior and posterior diameters of the eye being too long and the anterior surface of the cornea being too convex for external light to converge accurately on the fundus of the eye. Excimer laser correction (LASIK/PRK) uses a computer-controlled excimer laser to etch the corneal stroma in the pupil area according to the degree of myopia and the presence of astigmatism, resulting in a slight flattening of the anterior surface of the cornea. This allows external light to converge and image accurately on the retina at the base of the eye to correct myopia. Because the key to myopia surgery is the creation of the corneal flap, it is not advisable for highly myopic patients or those with thin corneas to undergo myopia surgery. However, after years of research, LASEK surgery can meet the desire of some highly myopic and thin corneal myopic patients to correct their refractive errors through a special flap fabrication method. Treatment for myopia: PRK laser technology requires removal of the corneal epithelium prior to treatment and then laser cutting on the cornea. This method is painful, easy to form corneal clouding, long medication time, slow recovery of vision, and low myopia treated. It is seldom used now and tends to be eliminated. LASIK (Lysaght) technology is used to treat myopia by first creating a 130-160um cornea with a micro lamellar knife, lifting the flap and then performing laser cutting on the stromal layer of the cornea. This method preserves the corneal epithelium and anterior elastic layer, thus conforming to the anatomy and physiology of the cornea. Theoretically, it is possible to treat any degree of myopia as long as there is sufficient corneal thickness. It is currently the mainstream method for the treatment of myopia. Because of the thick corneal flap, it requires high corneal thickness and the number of diopters to be corrected is limited by the thickness of the cornea, so it is not suitable for patients with high numbers and relatively thin corneas. The LASEK (Lysaght) technique is mainly for myopic patients with special conditions that are not suitable for LASIK treatment (such as thin corneas, high myopia, large curvature, small eye and lid fissures, etc.). The reason for this is that a certain safe thickness of cornea has to be reserved after myopia is treated by laser. LASIK treatment for myopia begins with the creation of a 130-160um corneal flap, whereas LASEK requires only a 50-70um corneal epithelial flap. lASEK preserves about 90um more corneal thickness than LASIK, which increases the safety of the treatment.