Role of spherical aberration in contrast sensitivity loss with radial keratotomy.

A technique is described to determine the change in image contrast as a result of the spherical aberration induced by the radial keratotomy procedure. The hypothesis that the loss in contrast sensitivity of the RK eye is due to the change in spherical aberration postsurgically, is found to be acceptable for some patients. However, this is not a sufficient explanation in all cases. This conclusion may be due to assumptions inherent in the technique derived for calculating spherical aberration or to other factors of importance in the post-RK eye.