Abstract

The effect on foveal dark adaptation of pre-exposure of the eye for brief durations to light of relatively low brightness was investigated. Monocular measurements of absolute brightness sensitivity (RL) were made with a modified Crozier-Holway discriminometer. A one degree square, centrally fixated test patch was presented for 0.033 sec. The course of dark adaptation as measured by the RL was investigated following pre-exposures of the dark-adapted eye to 0.10, 1.0, 10, and 100 ft-L for 1, 10, and 100 seconds. Dark adaptation was too slight to be measured by the techniques used in this investigation following pre-exposures of the dark-adapted eye to quantities of light in which the brightness×duration product was 100 foot-lambert-seconds or less. The extent of dark adaptation was found to increase as combinations of pre-exposure duration and brightness increased above that critical value.

© 1956 Optical Society of America

Studies on Dark Adaptation. II. The Pre-Exposure Tolerance of the Human Fovea Adapted to Different Brightness Levels*

Dorothea E. Johannsen, Patricia I. McBride, and Joseph W. Wulfeck
J. Opt. Soc. Am. 46(4) 266-269 (1956)

Studies on Dark Adaptation. III. Pre-Exposure Tolerance of the Human Fovea as Measured by Contrast Sensitivity*†

Joseph W. Wulfeck, Dorothea E. Johannsen, and Patricia I. McBride
J. Opt. Soc. Am. 50(6) 556-558 (1960)

Studies on Dark Adaptation. IV. Pre-Exposure Tolerance of the Dark-Adapted Peripheral Retina*

John A. Hanson, Joseph W. Wulfeck, and Edythe M. S. Anderson
J. Opt. Soc. Am. 50(6) 559-561 (1960)

Studies on Dark Adaptation. V. Effect of Various Sizes of Centrally Fixated Pre-Exposure Fields on Foveal and Peripheral Dark Adaptation*

John A. Hanson, Edythe M. S. Anderson, and Richard P. Winterberg
J. Opt. Soc. Am. 50(9) 895-899 (1960)

Studies on Dark Adaptation. VII. Effect of Pre-Exposure Color on Foveal Dark Adaptation*

John A. Hanson and Edythe M. S. Anderson
J. Opt. Soc. Am. 50(10) 965-969 (1960)