dark adaptation: Meaning and Definition of

dark' adapta"tion

Pronunciation: [key]
— Ophthalm. Ophthalm.
  1. the reflex adaptation of the eye to dim light, consisting of a dilatation of the pupil and an increase in the number of functioning rods accompanied by a decrease in the number of functioning cones (opposed to light adaptation).
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.