How often do you change your orthokeratology lenses?

Orthokeratology is a hard contact lens, its principle is to change the refractive state of the anterior surface of the cornea, to correct refractive error. Generally, it is worn before going to bed at night, and removed after getting up the next day. During the day, it is possible to achieve better vision without wearing glasses. Generally, vision is better in the morning, and vision may gradually decline at night. To wear again before going to bed, the cycle is repeated. Under normal circumstances, Orthokeratology is replaced once a year. If personal hygiene and operation are proper, and the lens is well protected, it can be extended for a period of time.