In this video, we continue our discussion of the human perceptual system by discussing how we perceive depth. Using a variety of examples and demonstrations, we focus specifically on the two types of cues critical for depth perception: monocular depth cues and binocular depth cues.

Monocular Depth Cues: Depth cues that only require one eye to see.

Binocular Depth Cues: Depth cues that require both eyes to see.

Relative Size: The first monocular depth cue, which states that, all else being equal, more distant objects tend to look smaller.

Texture Gradient: The second monocular depth cue, which states that object textures become less apparent farther away.

Interposition: The third monocular depth cue, which states that if Object A blocks our view of Object B, Object A must be closer to us than Object B; also known as “occlusion.”

Linear Perspective: The fourth monocular depth cue, which states that parallel lines converge as distance increases, eventually meeting at a vanishing point.

Height in Plane: The fifth monocular depth cue, which states that distant objects tend to appear higher in our visual planes than closer objects.

Light and Shadow: The sixth and final monocular depth cue, in which objects cast shadows that tell us their 3dimensional shapes.

Binocular Disparity: The first binocular depth cue; because our two eyes are offset, they produce two different images; our brains use the disparity between these images to calculate depth, with larger disparities meaning closer objects.

Binocular Convergence: The second and final binocular depth cue; looking at closer objects causes our eyes to converge; our brains use this information to calculate depth, with more convergence meaning closer objects.