An efficient ray tracing algorithm for modeling visual performance from corneal topography

The authors describe two ray-tracing algorithms for deriving an optical point-spread function (PSF) from corneal topography measurements: one a simple adaptation of the lensmaker´s equations, the other a classical geometric refraction. The relative efficiency of the two algorithms is objectively evaluated in terms of actual computer time. The overall difference in the resulting PSFs is characterized by means several statistical measures, and subjective evidence of the accuracy of modeling visual effects is presented