Abstract

Measurements were made of the change of threshold during and after exposure to scotopically and photopically equivalent spectral lights using a constant small b wave in the frog’s electroretinogram as criterion.

After exposure to spectral lights of equal photopic luminance, the rod branch of the dark-adaptation curve occurs earlier after orange than after blue adaptation while the cone branches are the same. After exposure to lights of equal scotopic luminance, during the cone branch of the dark adaptation curve the threshold is higher after orange than after blue adaptation while the rod branches are the same.

Incremental thresholds have been determined for test lights of various wavelengths at stepwise increased levels of adaptive illumination with orange and blue lights of equal scotopic efficiency. With blue adaptation the loss of blue sensitivity is as large as the loss of orange sensitivity with orange adaptation whereas the effect of blue adaptation on orange sensitivity is much smaller than the loss of blue sensitivity with orange adaptation. It is concluded that blue light mainly depressed the rods while orange light depresses rods and cones in more nearly equal proportions. No test light was found which would change the increment threshold equally with orange and blue adaptation.

The use of blue glasses is recommended to preserve a high cone sensitivity during and after exposure to bright lights of equal scotopic efficiency.

© 1961 Optical Society of America

Analysis of Photopic and Scotopic Function in an Incomplete Achromat*

Irwin M. Siegel, Clarence H. Graham, Harris Ripps, and Yun Hsia
J. Opt. Soc. Am. 56(5) 699-704 (1966)

Photochromatic Interval during Dark Adaptation and as a Function of Background Luminance*

Lothar Spillmann and Jane E. Conlon
J. Opt. Soc. Am. 62(2) 182-185 (1972)

Spectral Sensitivity of Single Neural Units in the Bullfrog Retinal*

Robert M. Chapman
J. Opt. Soc. Am. 51(10) 1102-1112 (1961)

Extrafoveal spectral sensitivity during dark adaptation

Bjørn Stabell and Ulf Stabell
J. Opt. Soc. Am. 70(1) 81-86 (1980)

Spectral sensitivity of the dark-adapted extrafoveal retina at photopic intensities

Ulf Stabell and Bjørn Stabell
J. Opt. Soc. Am. 71(7) 841-844 (1981)