Method for diagnosing and improving vision

In a method for treating the cornea of an eye to improve vision, said method being performed with the aid of a computer system running a topological modeling computer program which, making use of sampled points on the cornea for which the coordinates are known relative to a reference plane, produces a surface model of said cornea which closely represents the surface of the cornea, said method comprising the steps of:

• defining the periphery of a working area of the cornea by the intersection between the surface model and a cylinder of predefined diameter, the axis of which is perpendicular to the reference plane and passes through the point on the surface model, the HIGH POINT, which is most distant from the reference plane;
• defining the LOCAL Z AXIS as a line passing through the HIGH POINT which is perpendicular to a plane that most closely contains the periphery of the working area;
• creating a plurality of characterizing curves each defined by the intersection with said surface model of a plane containing the LOCAL Z AXIS, the plane being in different rotational positions about the LOCAL Z AXIS for at least two of the characterizing curves;
• modifying the shape of the at least two characterizing curves so that the radius of curvature therealong is changed in accordance with the diopter correction required at the at least two characterizing curves as previously determined from a vision test performed on the eye;
• constructing a corrected surface model in which the portion of the surface bounded by the periphery of the working area matches the at least two modified characterizing curves and varies smoothly therebetween;
• and
• utilizing the corrected surface model to control the shape of at least a portion of a surface of a contact lens for use in the eye.