Computer aided contact lens design and fabrication using spline surfaces

A system for contact lens fabrication using one or a plurality of piecewise functions that satisfy a set of associated constraints of smoothness, where the contact lens is specified by said piecewise functions, and where said method is applicable to rotationally symmetric surfaces or non-rotationally symmetric surfaces or both rotationally symmetric and non-rotationally symmetric surfaces:

• (i) acquisition of topographic data of a cornea,
• (ii) construction of three-dimensional mathematical surface model of said cornea,
• (iii) determination of the posterior surface of a contact lens resulting from insertion of a tear layer between the cornea surface and posterior surface,
• (iv) computation of the anterior surface of the contact lens to provide optics, and
• (v) fabrication of said lens using a computer numerical control manufacturing device selected from the group comprising lathes, grinding and milling machines, molding equipment, and lasers.