Assessment of binocular vision utilizing the Pulfrich and Venetian blind effects

Pulfrich revisited

The Pulfrich phenomenon is a stereo-illusion resulting from latency disparities in the visual pathways. It is common after optic neuritis, but is also to be found with other conditions. The symptoms are often difficult for the patient to explain and for the physician to understand. Symptoms may be sufficiently disturbing to significantly interfere with a patient's life (e.g., prevention of driving). Treatment with the use of monocular tints is simple and effective.

The Pulfrich effect: filtering portions of both eyes

This study investigated apparent depth and pattern using four conditions of hemiretinal filtering with 19 male and five female college-student SS. The results for both the depth and pattern of pendulum movement challenge the adequacy of the long-standing latency hypothesis. Apparent depth occurred without simultaneous stimulation disparity and smooth figure-8 patterns resulted only when the stimulation disparity was induced for both cortical hemispheres. The findings suggest independence of depth and pattern processing in the central nervous system and underscore the importance of viewing perception as an active constructive process.