A Simplified Computation of the Front Curve of a Contact Lens

Abstract

The practitioner and laboratory technician require the exact radius of the front curve of a contact lens to permit fabrication, calculation of front vertex power, thickness of magnification calculations and specification of an anterior lenticular curve.While tables, monographs and slide rules are available for this purpose, they are not always accessible or complete. We shall derive a simpler linear expression for the anterior radius of a contact lens which obviates the need for complex tables or involved computational procedures.The classical expression relating back vertex power, base curve, thickness and front curve stem from the basic Gaussian equation: