Nearsightedness in one eye is also myopia, and in the case of myopia, the degree of myopia is not reversible by any means. For monocular myopia, the only way to change its refractive state is through laser or intraocular IOL implantation in adulthood, but for the eye axis, there is no means to change it. The main cause of myopia is the blurred image of a distant image in front of the retina, which must be moved to the retina by a concave lens to see clearly. For the development of myopia, the main causes are elongation of the eye axis and changes in corneal curvature, and both of these, such as elongation of the eye axis, cannot be made shorter by various means.