ABSTRACT The purpose of this study was to clinically evaluate the merits of an aspheric front surface contact lens. Subjects were selected on the basis of a manifested residual astigmatism with reduced visual acuity through conventional spherical contact lenses. The subjects were then fitted with the experimental lens. An analysis of the data indicated that there was a mean increase of 6.54 percent Snell‐Sterling visual efficiency. It was found that with the experimental lens there were statistically significant improvements in visual acuity (p<0.01). Since the measured clinical residual astigmatism did not vary, the improvement in visual acuity may be attributed to a reduction of spherical aberration. It was found that the pupil size and lens centration were not critical factors. The results of this study suggest that the aspheric front surface contact lens can be prescribed with a large degree of confidence toward restoration of visual acuity in those patients manifesting residual astigmatism.
Ronald L. Kerns (Tue,) studied this question.