DESIGNING METHOD OF CONTACT LENS BY PROGRAM CONTROL AND CONTACT LENS BY SAID METHOD

摘要

PROBLEM TO BE SOLVED: To provide a lens and its shape designing methods which can ensure the smooth joining or shift between the adjacent areas of the lens having different thickness and different curvature radiuses especially for a toric lens and its shape and also can perform the machining of the lend even with an NC (numerically controlled) machine tool which is operated by a program. SOLUTION: The functions f (a) and f (b) are defined to describe 1st and 2nd segment curves on the surface of a lens. Then a grade dy/dx is calculated between both functions f (a) an f (b) in a shift band set between the 1st and 2nd segments of the lens surface. A function is defined to describe a desired shift band between both segments. Then a program is produced based on both functions f (a) and f (b), the grade dy/dx and the function describing the desired shift band, so that an NC machine tool can machine the desired shift band between the 1st and 2nd segments of the lens surface.