Spot diagrams are computer generated by skew ray tracing for a model of the human eye which is corrected by means of a contact lens and spectacle lens. An examination of the images of a point source of light at 0° and 20° off the optical axis of the eye-lens system are shown. For the correction of aphakia, the performance of the contact lens is shown to be superior in off-axis optical performance. © 1975 American Academy of Optometry.
