Are OK lenses contact lenses? What's the harm of OK mirror? Can you permanently adjust your vision with a mirror?

Ok lens is a contact lens, now called orthokeratology, rgp. The difference from ordinary invisibility is that it is hard. Because it has a certain hardness, the curvature of cornea changes with the hard shape, so as to achieve the purpose of correction. Changing the shape of the cornea is a long-term oppression of the cornea. This defect is that after a long time, the center of cornea tends to become thinner, which can not bear the pressure of aqueous humor in the eye and will cause a series of symptoms. The cornea is the best example, which is easy to scratch. It is also very important that the cornea needs to breathe, and it can only absorb oxygen from the outside. However, wearing this kind of contact will deprive the cornea of oxygen absorption and affect the normal metabolism and physiology of the cornea. After a long time, it is easy to cause corneal cell death, shedding, inflammation, dry eye and even corneal perforation. The so-called high oxygen permeability is relative. Orthokeratology came from America, but there were no orthokeratology ophthalmologists in America after 2004. The so-called fda certification in China is 00.