Contrast in night vision.
D003623:Dark Adaptation; D005829:Geniculate Bodies / Q000502:physiology; D006801:Humans; D008029:Lighting; D011601:Psychophysics; D012160:Retina / Q000502:physiology; D013028:Space Perception; D014793:Visual Cortex / Q000502:physiology; D014794:Visual Fields