Why Two Eyes Beat One

Explaining depth perception means combining receptor layout, binocular geometry, monocular cues, and top-down interpretation into one account of a single scene.

One ordinary scene — a hallway with a person at the far end — worked through completely: what each retina receives, how the disparity is computed, which monocular cues carry the far distance where disparity fails, how constancy holds the person's size steady as they approach, and where expectation fills what the data underdetermine. Ends by naming what changes if one eye is closed and what does not.