Corneal optics from videokeratographs.

Recent developments in measuring corneal topography make possible an improved understanding of corneal optics. It is shown, using a wavefront analysis, that optical quantities of interest follow from knowledge of sagittal depths of a cornea, and that sagittal depths are provided by or readily found from the output of commercially available instruments. The errors for normal corneas are expected to be quite small based on measurements on calibration spheres and ellipsoids. As an example the optical consequences of a peripheral asymmetry are estimated for a particular normal cornea.