The keratoplasty lens is designed for children to stop myopia from deepening. The keratoplasty lens (also known as OK lens) was developed by a group of American ophthalmologists and has been used clinically for 50 years in the United States, Japan and Germany. Currently, it is used in 34 countries around the world, mainly to stop myopia from deepening in children. As of 2010, more than 600,000 children in China have used it. It is worn on the eye while sleeping, and it flexibly massages the eye, gradually flattening the curvature of the cornea and shortening the eye axis, thus effectively stopping the development of myopia, and is known as “the technology that controls and corrects myopia while sleeping. It adopts an inverse geometric design, with the inner surface consisting of multiple arcs. The hydrodynamics generated by the device changes the geometry of the cornea to correct myopia. When you wake up in the morning and take it off, your child’s vision returns to the best state, usually above 1.0, so you no longer need to wear any glasses during the day for studying and playing. While controlling the deepening of myopia, it frees the child from the bondage of glasses and reduces the occurrence of accidents caused by glasses.