What are keratomileusis? What is the principle of correcting myopia? Keratomileusis is a gas permeable rigid corneal contact lens material, which was developed based on the non-breathable rigid material PMMA. The “OK lens” often seen in the market is actually the prototype of keratomileusis, but keratomileusis is an evolutionary version of the former. It uses a special inverse geometric design of the keratoplasty lens, the inner surface of which consists of several curved segments. The lens is unevenly distributed with the tear layer, and the resulting hydrodynamic effect changes the geometry of the cornea, which is worn at the front of the cornea while sleeping, gradually flattening the curvature of the cornea and shortening the eye axis, thus effectively stopping the development of myopia, which is described by the public as “a technique that is worn at night and restores normal vision the next day”. Keratomileusis is an effective reversible treatment for non-surgical removal of myopia through the use of specially designed keratomileusis lenses that symmetrically and progressively change the shape of the central surface of the cornea; similar to laser surgery, but unlike laser surgery, keratomileusis produces temporary and reversible results. Keratomileusis is an effective medical device that inhibits further myopia and is highly effective in controlling vision in adolescents, allowing vision to return to normal in a very short period of time. The keratoplasty lens is a medical device, and the prescription is a medical act, so in order to use it safely, you must go to a regular eye hospital for fitting.