sentences:  The circular scanning of the lens's optical axis traces out a coaxial cone pattern with the convergence point as its apex.Early tests revealed that the brain will translate parallax scanned information into depth information at scanning frequencies of between 3–6 Hz, and that the ideal frequency is 4.31 Hz.In his 1995 book, Foundations of Vision, Brian Wandell states, "Perception is an interpretation of the retinal image, not a description.