Abstract: A system for adjusting the curvature of the cornea of the eye involves inserting a plastic split end adjusting ring into the stroma of the cornea by first making a first incision in the cornea above the corneal ring at about the eight millimeter chord, then inserting one end of a metal split end dissecting ring into the incision with the trailing end of the dissecting ring remaining outside the cornea. The one end of the dissecting ring has a transverse hole therein near its tip end. The dissecting ring is held by a magnetic holding and rotating device which has a concave end surface and circular groove therein for receiving the metal dissecting ring and for holding it in a circular shape. As the holder is rotated the inserted end of the metal ring is magnetically forced to follow rotation of the holder thus the dissecting ring is inserted in a circular path within the stroma.