The Pulfrich effect has been characterized as a perception of depth produced by image disparity when the stimulus to one eye is less bright than that to the other. A method has been devised which permits ostensible binocular vision but gives a monocular stimulation to each eye in succession, so that no portion of the pathway of the oscillating stimulus is visible to both eyes at the same time. Under this condition, the perception of depth is still reported, thus damaging the latency hypothesis based on binocular vision as an explanation of the phenomenon.
MILTON S. KATZ and IRA SCHWARTZ, "New Observation of the Pulfrich Effect," J. Opt. Soc. Am. 45, 523-523 (1955)