If you just want to see better when testing your eyesight, start wearing it three days before the test. If you don't wear glasses all the time, wear them every day, but pay attention to personal hygiene. I don't know about the damage, at least I didn't do any harm when I used it myself.

Hangzhou is not very clear. Chang Zheng Ruijin and Shanghai Armed Police Hospital seem to be equipped with orthokeratology lenses.

In addition, your topic is plastic mirror, and the content is contact lens. This is not right. Orthokeratology and contact lenses are completely different things and have different uses. Corneal contact lens is what we often call contact lens, which is divided into soft contact lens and hard contact lens. Soft contact lenses are traditional contact lenses on the market, and hard contact lenses are RGP. Soft contact lenses have low requirements for fitting, while RGP has high requirements for fitting, and the price is many times higher than that of soft contact lenses.

Generally speaking, contact lenses are glasses worn on the cornea. Orthokeratology can be used to adjust the state of exophthalmos, so that the cornea can return to the position of non-myopic ball, thus achieving the purpose of reducing the degree. This is what contact lenses can't do.