title: Effect of illuminance on the directions of chromostereopsis and transverse chromatic aberration observed with natural pupils.
abstract: The direction of chromostereopsis observed with a natural pupil and the direction of the monocularly perceived disparity between coloured targets (F and C lines - 486 and 656 nm) have been measured in a sample of 30 subjects at 10 and 1000 lx. At both illumination levels approximately equal numbers of subjects perceived positive and negative chromostereopsis. When the ambient illumination was increased, a reversal in the direction of the chromostereopsis occurred for 16 subjects. For six of them a change from a positive to a negative chromostereopsis was observed, a pattern not reported in previous studies. In most cases at both high and low illuminance, there was an absence of perception of a monocular disparity (transverse chromatic aberration), although chromostereopsis was reported, indicating that binocular information can be obtained from sub-threshold monocular disparities. At low illuminance, the lack of correlation between the direction of chromostereopsis and transverse chromatic aberration (TCA) may indicate that there may be a supplementary binocular factor in chromostereopsis.
authors.affiliation: School of Optometry, University of Waterloo, Ontario, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Simonet
authors.forename: M C
authors.initials: MC
authors.lastname: Campbell
mesh_terms: D000328:Adult; D003118:Color Perception / Q000502:physiology*; D003867:Depth Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D008875:Middle Aged; D011680:Pupil / Q000502:physiology; D013053:Spectrophotometry; D014794:Visual Fields