Indications for keratomileusis: 1, myopic patients who need high naked eye vision and cannot receive frame or contact lens correction and surgical treatment; 2, adolescents with rapid myopia development (age > 8 years old, with some self-care ability, children need parental supervision); 3, myopia ≤ -600D, astigmatism ≤ -1.50D (parsimonious astigmatism); 4, corneal curvature range 41D -46D, too large or too small correction difficulties; 5, no other eye and systemic diseases; 6, able to understand the mechanism of action of keratoplasty and potential problems and limitations of correction; 7, clear motivation and very good compliance, good hygiene habits, can follow up regularly according to medical advice; 8, have a certain economic base, can afford the cost of treatment period. Contraindications to keratoplasty: 1. misconceptions about keratoplasty treatment, high expectations or unrealistic beliefs that the method can cure myopia; 2. refractive error >-6.00D, retro-regular astigmatism, cis-regular astigmatism >2.00D is not suitable for night wear; 3. patients with significant intraocular astigmatism, the ratio of spherical to columnar lenses in the correction of refractive error is less than 2; 4. pupils Large, especially those with large pupils at night; 5. Ocular disorders: epithelial cell lesions, endothelial cell lesions, cone keratoconus, recurrent epithelial cell spotting, corneal hypo-intuition and severe dry eye and infections, inflammatory diseases, incomplete eyelid closure, paralytic strabismus, nystagmus, lens clouding and acute and chronic glaucoma, acute inflammation in any active phase of the eye, chronic uveitis, chronic dacryocystitis, etc.; 6. Systemic contraindications: severe diabetes, rheumatoid arthritis and other immune diseases and psychiatric patients, etc.; 7. Relative contraindications to individual conditions: relatively poor personal hygiene, poor compliance and inability to review on time; 8. Allergic to components in the care products.