It is recommended to stop wearing OK lenses, i.e. keratoplasty lenses, seven days to one month after stopping wearing keratoplasty lenses before taking visual acuity measurements and other operations. Since keratoplasty lenses are worn at night to shape the cornea, pressing a suitable degree of depression in the cornea to achieve the purpose of optical correction, the recovery of the corneal depression requires a certain amount of time, and only after the original convexity is completely restored, can the optometry and prescription be performed accurately, and it takes one week to one month according to the different conditions of the individual. After stopping wearing keratoplasty lenses for one week to one month, before performing vision measurement, to ensure full recovery, you can go to the hospital to measure the corneal curvature and other data, so that you can compare the corneal data before wearing them. For details, please consult a medical professional for advice.