Related Experiment Video
Updated: Jun 19, 2026

Visualizing Visual Adaptation
Published on: April 24, 2017
THE DARK ADAPTATION OF THE COLOR ANOMALOUS MEASURED WITH LIGHTS OF DIFFERENT HUES
1Department of Psychology, The Johns Hopkins University, Baltimore.
Abstract:
Determinations of minimum light thresholds as a function of time in the dark have been made for four color normal, three deuteranopic (or deuteranomalous), and four protanopic (or protanomalous) subjects. Measurements were made with red, reddish orange, yellow, green, violet, and white test lights. Dark adaptation curves for the deuteranopes and deuteranomalous are essentially identical with those of the color normal for all colors. The cone portions of the protanopic dark adaptation curves measured with the red, reddish orange, yellow, and white lights are higher than the corresponding data for the color normal, the discrepancy between the two sets of data decreasing from the long to short wave lengths. Dark adaptation curves for the protanopes and protanomalous measured with green and violet light are essentially normal in appearance. A theoretical explanation is advanced to account for these findings in terms of the known sensitivity characteristics of the normal and color-anomalous eye.
Related Concept Videos
Photoreceptors and Visual Pathways
Color Vision
Pigmentation
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
Photoreceptors and Plant Responses to Light
Changes in Skin Color: Clinical Perspectives
Albinism
Albinism is a genetic disorder that affects (completely or partially) the coloring of skin, hair, and eyes. The defect is primarily...
Channel Rhodopsins
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...

