We studied the effects of isoluminant stimuli on the cyclovergence mechanism.
Some previous studies report that stereo depth perception is compromised at isoluminance.
Other studies report that rotation disparities affect ocular torsion, which affects perceived inclination of stereo images. The luminance of the red, R0-plane was randomly varied. Presentation duration varied between 2 s and 12 s and the perceived inclination of the G4 pattern was measured. At 7-s duration, a gradual change in inclination indicated a decreasing effect of R0 as it approached isoluminance, with a sharp compromise directly at the isoluminance point. Isoluminance clearly affected relative inclination of R0 and G4, from which we infer reduced stimulation to the cyclovergence system.