Twenty patients with various dysfunctions of the optic nerve were subjected to examinations by means of a test based on the Pulfrich's phenomenon. The Pulfrich's effect was observed in 18 among them. The survey of the phenomenon was continued in 5 patients in the course of the treatment. It was detected that the dimension of the spontaneous Pulfrich's illusion diminishes gradually tending towards norm. The results obtained assure us of the usefulness of the application of the Pulfrich's effect as a diagnostic test in ophthalmology and neurology.
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June 2011
University of Glasgow, Glasgow, UK.
First described in 1922 by Carl Pulfrich, the Pulfrich effect is a stereo-illusion thought to be caused by an inter-ocular signal latency difference stimulating neurons jointly tuned to disparity and motion. Clinically, this can be a spontaneous manifestation due to various ocular and central visual pathway pathologies, and cause symptoms independent of a range of routine visual parameters which may seem bizarre to both the patient and the clinician. Eliciting such symptoms of difficulties with motion and depth perception in a clinical history should direct the clinician to the possibility of the presence of the spontaneous Pulfrich effect, and to proceed to test for it.
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