Orthokeratology lenses (ortho-K lenses), also known as OK lenses, are rigid, gas permeable contact lenses with an inverse geometric design that are flat in the center and steep in the periphery. The use of keratoplasty lenses is a reversible, non-surgical physical orthopaedic treatment. Indications and non-indications for keratoplasty: 1. Indications and basic conditions for the selection of wearers: (1) Should both be myopic and regular astigmatic patients and meet the following basic conditions: (a) The amount of myopia can be corrected in the range of -0.25 to -6.00 D, with less than -4. 00 D as the ideal correction range. (b) Corneal astigmatism less than 1.50 D and cis-regular astigmatism are relatively appropriate. (c) Corneal curvature between 42.00 and 46.00 D. Corneal curvature that is too flat or too steep should be prescribed at the discretion of an experienced physician; (d) Corneal morphology that is progressively flatter from the center to the periphery with a larger “e” value is relatively suitable; (e) Normal sized pupils. ) normal size pupil. (2) Patients who are able to understand the mechanism of action and practical effects of keratoplasty and have very good compliance, who can follow medical advice to review and change lenses on time. (3) May be suitable for children and adolescents with rapid progression of myopia, but minor children need to be supervised by their parents and determined to have the proper self-care ability for lens fitting. Children too young (<8 years old) with special needs will be considered at the discretion of the physician and with increased monitoring for safety. 2. Non-indications: (1) Ocular or systemic disorders, all contraindications to contact lens wear. (2) Inability to understand the limitations and reversibility of keratoplasty for myopia correction. (3) Refractive error and corneal status that do not meet (a) to (d) of the former indications (1), along with high expectations beyond the therapeutic range of keratoconus. (4) Patients with excessive sensitivity. (5) Poor compliance, inability to review on time, and inability to carefully care for, clean and replace lenses as ordered by the physician.