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dark adaptation

noun, Ophthalmology.
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).
Origin of dark adaptation
First recorded in 1905-10
Related forms
dark-adapted, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2017.
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Examples from the Web for dark adaptation
Historical Examples
  • To come now to the sense of sight, we have light adaptation, dark adaptation, and color adaptation.

    Psychology Robert S. Woodworth
  • dark adaptation is equivalent to sensitizing the retina for faint light.

    Psychology Robert S. Woodworth
dark adaptation in Medicine

dark adaptation n.
The adjustment of the eye under reduced illumination, in which sensitivity to light is greatly increased. Also called scotopic adaptation.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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