Recently many myopic friends are asking me about myopia surgery, I will instruct him/her to stop wearing contact lenses for a week, or more than 1 month in the case of rigid keratoplasty lenses (such as OK lenses). So why do you need to stop wearing contact lenses before myopia surgery? There are two reasons: One, stopping contact lenses is to normalize the corneal epithelium. Because contact lens wear often makes the cornea hypoxic, and in severe cases even cause corneal epithelial defects. It takes 24-48 hours for the corneal epithelium to recover from the lack of oxygen, especially the defective corneal epithelium. If the contact lens has caused corneal inflammation, it will take one month for the corneal inflammation to be fully controlled before surgery can be performed. Secondly, the original shape of the cornea should be restored so as not to affect the preoperative refractive examination and thus the accuracy of the surgical correction. Contact lenses have a “shaping” effect, their long-term wear will more or less affect the shape of the cornea, different types of contact lenses (different materials, different curvature, and the degree of matching the shape of the cornea), different corneal properties of patients (thickness, texture, hardness, elasticity, etc.), resulting in contact lenses on the shape of the cornea The degree of influence of contact lenses on the shape of the cornea varies, so no generalizations can be made. In general, it is sufficient to stop wearing ordinary contact lenses for one week and rigid keratoplasty lenses (such as OK lenses) for one month or more.