Contact lens and a method for manufacturing contact lens

摘要

A contact lens having a smooth surface is made through use of a computer implementing a spline approximation of corneal topology. Piecewise polynomials approximating the corneal topology have equal first and second derivatives where they join. A curve representing the central optical portion of the lens and the piecewise polynomial adjacent to the central optical portion curve have an equal first derivative where they join. A contact lens is cut corresponding to the smooth surface defined by the piecewise polynomials.