Patent ID: 7659971

Claim:
A lensometer for measuring waveshaping properties of a spectacle lens across at least a portion of the spectacle lens, the lensometer comprising: a light source for emitting light; beam-tailoring optics that receives light from said light source and outputs a light beam having a beam size at least as large as said portion of said spectacle lens to be measured, said light source, said beam-tailoring optics, and said spectacle lens disposed along an optical path such that said light beam propagates through said spectacle lens, wherein said beam is expanded so as to increase said beam width from between about 10 to 20 millimeters to between about 20 to 80 millimeters; and a Talbot plane self-imaging wavefront sensor disposed in said optical path to receive said light beam after said beam has passed through said spectacle lens, said Talbot plane self-imaging wavefront sensor configured for use in determining the waveshaping properties of the spectacle lens based at least in part on a near field diffraction pattern.