Visual depth perception of a 10-month-old monocular human infant.

A monocular infant tested on the "visual cliff" crawled over glass which had a patterned surface just beneath it and would not cross glass which had the same pattern 40 inches below its surface. Since this infant, using only monocular visual cues, was able to discriminate depth, the experiment disproves a general belief in the primacy of binocular cues in depth perception.