The range of degrees of myopia that can be corrected with keratoplasty is usually between 100 and 600 degrees of myopia. Myopia less than 100 degrees usually does not require much correction because the impact on vision is relatively small and is mainly observation-based. And this kind of low myopia, wearing keratomileusis is not very effective and corrective effect, so usually first by wearing a frame to observe, if it does rise quickly, only then will use OK lens to control. If the myopia is greater than 600 degrees, there may be no way to fully correct it by wearing keratoplasty, that is, wearing OK lenses one night, there is no way to maintain the vision to more than 1.0 during the day. However, it is worth emphasizing that even if the degree of myopia is higher than 600 degrees and frame glasses are needed to assist in improving vision, the effect of keratoplasty on myopia control for these children is still there, that is, even if the degree of myopia is higher than 600 degrees, keratoplasty lenses can be worn to prevent further deepening of the degree.