Key points are not available for this paper at this time.
School of Optometry, Ohio State University *An abridgment of the material presented before the Ohio Section of the American Physical Society, May 6, 1944, at Columbus, Ohio. Submitted on June 26, 1944, for publication in the September, 1944, issue of the AMERICAN JOURNAL OF OPTOMETRY AND ARCHIVES OF AMERICAN ACADEMY OF OPTOMETRY.
Henry W. Hofstetter (Fri,) studied this question.