Keratomileusis: originated in the United States, after 50 years of development, has been used in 34 countries around the world; it is the use of a special inverse geometric design of keratomileusis lenses, worn in front of the cornea during sleep, gradually make the curvature of the cornea flattened, the eye axis shortened, thus effectively stopping the development of myopia, known as “sleep can control and correct myopia technology It is known as “the technology that controls and corrects myopia by sleeping.