Hartmann test modification for measuring ophthalmic progressive lenses

We describe a modified verion of the Hartmann test in which the pattern of the holes is replaced with a circular scanning laser beam. A position-sensitive detector is used to acquire the coordinates of the deflected beam. Significant data are obtained when the Fourier transform of the detector output signals is considered. Application of this test method to the mapping of optical parameters of ophthalmic progressive addition lenses is presented. Prismatic deviation, spherical power, and astigmatism are measured with appropriate accuracy.