Generally speaking, soft things will change shape with hard things, our eye cornea is soft, myopia prevention keratoplasty lens hardness is higher than the cornea hardness, so in the process of wearing the lens, will gradually through physical methods to make the cornea a shape change, this phenomenon is actually the principle of ophthalmology scientists invented keratoplasty lens, foreign countries in recent years with this method to the cornea to produce a reasonable shaping treatment to prevent and control myopia.