Methods and apparatus (610)are disclosed for diagnosing vision and improvingvision in a manner which does not interfere with the natural shape of thecornea or its orientation relative to the remainder of the eye, but whichchanges its surface curvature appropriately to achieve the required correctionof vision. The focus of the cornea (14) is adjusted so that different regionsfocus substantially to the same axis and preferably to substantially the samepoint on the axis. This can be accomplished by shaping the cornea (e.g.through ablation) or by applying an appropriate contact lens or other opticallens. In either case, correcting the central portions of the cornea shouldhave a more significant effect on correcting focus scatter than correcting themore outward portions.
