Abstract

Visual acuity at three contrasts and two brightnesses, and critical flicker frequency (CFF) at two brightnesses, were measured morning and evening on 24 subjects for five successive days. During the days the subjects drove automobiles for several hours, in the brilliant sunshine of the Arizona desert. Statistical analysis of the results shows that the acuity and flicker measurements have high correlation, but that the inherent variance of visual acuity measurements is great, while that of CFF is small. The CFF can be used to develop a logarithmic index of retinal sensitivity. Application of this index to the effect of exposure to sunlight is exemplified. Other applications are suggested.

© 1952 Optical Society of America

The Effect of Pupil Size on Visual Acuity for Photometrically Equated Test Fields at Various Levels of Luminance*

Herschel Leibowitz
J. Opt. Soc. Am. 42(6) 416-422 (1952)

Studies of Psychophysical Methods for Measuring Visual Thresholds*†

H. Richard Blackwell
J. Opt. Soc. Am. 42(9) 606-616 (1952)

Color and the Intensity-Time Relation*

Richard O. Rouse
J. Opt. Soc. Am. 42(9) 626-630 (1952)

Visual acuity in the presence of retinal-image motion*

Gerald Westheimer and Suzanne P. McKee
J. Opt. Soc. Am. 65(7) 847-850 (1975)

Retinal ganglion-cell density and receptive-field size as determinants of photopic flicker sensitivity across the human visual field

Antti Raninen and Jyrki Rovamo
J. Opt. Soc. Am. A 4(8) 1620-1626 (1987)