title: Relation between simultaneous spatial-discrimination thresholds and luminance in man.
abstract: Simultaneous spatial-discrimination thresholds of 6 human subjects were measured at luminances between 0.2 and 2000 cd/m2. Subjects were tested on a forced-choice discrimination task which required them to distinguish between test and control stimuli of high contrast square-wave gratings with similar space-average luminances. The form of the function depicting the relationship between acuity and luminance is similar to that obtained by other researchers. The estimated maximum acuity of 72 cycles/degree (c/deg) is higher than the commonly cited value of 60 c/deg and this is probably due to the combination of the high stimulus luminance and the psychophysical technique employed in this study.
mesh_terms: D000328:Adult; D004192:Discrimination, Psychological / Q000502:physiology*; D005260:Female; D005584:Fovea Centralis / Q000502:physiology; D006801:Humans; D008027:Light; D008297:Male; D008875:Middle Aged; D011601:Psychophysics; D012684:Sensory Thresholds; D013028:Space Perception / Q000502:physiology*; D014792:Visual Acuity