Visual purple Meaning, Definition & Usage

  1. noun a red photopigment in the retinal rods of vertebrates; dissociates into retinene by light
    rhodopsin; retinal purple.

WordNet

Definitions
  1. (Physiol.), a photochemical substance, of a purplish red color, contained in the retina of human eyes and in the eyes of most animals. It is quickly bleached by light, passing through the colors, red, orange, and yellow, and then disappearing. Also called rhodopsin, and vision purple. See Optography.

Webster 1913