Abstract

Luminance thresholds for the visual resolution of various widths of alternating light and dark lines were determined at various times during dark adaptation. The finest gratings, representing high degrees of visual acuity, show only a single cone curve that drops from a high luminance threshold during the first moments of dark adaptation to a final steady level that is reached after about 7 to 10 minutes in the dark. Coarse gratings produce a duplex curve that shows an initial cone portion and a delayed rod portion. Visual acuity is a parameter that sets the position of a given curve on the log threshold axis. The higher the degree of resolution required, the higher the dark adaptation threshold. At a constant grating luminance, visual acuity rises rapidly to a maximum during dark adaptation; the higher the luminance, the earlier and more rapid the rise and the higher the maximum. Visual acuity increases at all dark adaptation times with increase in luminance.

© 1953 Optical Society of America

Effect of Different Preadapting Luminances on the Resolution of Visual Detail During Dark Adaptation*

John Lott Brown
J. Opt. Soc. Am. 44(1) 48-55 (1954)

Relation of Threshold Criterion to the Functional Receptors of the Eye*

John L. Brown, Margaret P. Kuhns, and Helmut E. Adler
J. Opt. Soc. Am. 47(3) 198-204 (1957)

The Instantaneous Threshold and Early Dark Adaptation*

Howard D. Baker
J. Opt. Soc. Am. 43(9) 798-803 (1953)

Change of Threshold during Light and Dark Adaptation Following Exposures to Spectral Lights of Equal Scotopic and Equal Photopic Efficiencies*

Eberhard Dodt and Karl-Heinz Jessen
J. Opt. Soc. Am. 51(11) 1269-1274 (1961)

Duration and Light-Dark Ratio of Intermittent Preadaptation as Factors Influencing Human Dark Adaptation*

Eleanor R. Adair
J. Opt. Soc. Am. 43(1) 22-24 (1953)