Full field measurement of progressive lenses within seconds

We introduce an instrument to measure aspherical optical surfaces, e.g., eye-glasses. The sensor was developed by the University of Erlangen and 3D-Shape in cooperation with the eye-glass manufacturers Rodenstock, Rupp+Hubrach and Carl Zeiss. The sensor is based on "phase-measuring deflectometry": a sinusoidal grating is observed via the surface under test. From the phase variation within the observed image, the local slope of the surface and the local curvature can be determined. By use of at least two cameras, absolute measurements are possible. The sensor measures a curvature map of the full eyeglass within less than 10 sec. A measuring uncertainty of less than ±0.02 D is achieved, for a wide range of refractive power. The project was funded by the Bayerische Forschungsstiftung.