1. A variable anamorphic lens system comprising: (a) an optical element defining an optical axis and having a first optical surface substantially ahead of a plane perpendicular to said optical axis, (b) a second optical surface substantially behind said plane perpendicular to said optical axis, and (c) said first optical surface of said element being configured at variable distances relative to said perpendicular plane wherein thickness variation of said element causes a variation of effective focal length of said optical system as defined by the equation EQU Z.sup.2 (X.sup.2 +Y.sup.2)=K.sup.2, where X.sup.2, Y.sup.2 and Z.sup.2 are the coordinates relative to the lens axis and K.sup.2 is a constant defining the extent of the curvature of the surface of the optical element.