How We Perceive Depth (Monucular and Binocular Depth Cues)

The eye (i.e., the retina) receives sensory input in only two dimensions (length and width). It is therefore the brain’s task to make these cues into a three-dimensional perception.

This task is conducted by the use of monocular (one eye) depth cues and binocular (both eyes) depth cues. Here is a list of the depth cues that the brain uses to make the work seem three-dimensional (3D).

Monocular depth cues:

  • Patterns of light: Different patterns of light can be used to illustrate depth (e.g., in painting)
  • Shadow: Shadows can be used to illustrate depth (e.g., in a painting)
  • Linear perspecive: Parallel lines converge as they become more distant
  • Interposition: Nearby objects may cut off parts of our field of vision
  • Height in the horizon: The objects that are distant seem closer to the horizon
  • Texture: The texture of an objects appears sharper when it approaches
  • Clarity:  We see nearby objects more clearly

Binocular depth cues:

  • Binocular disparity: Each eye sees a slightly different image
  • Convergence: The muscles of the eye turns the eye inward to view close object
Photo: Skylinephoto