Breadcrumb Home > Dictionary > Index D dark adaptation: Meaning and Definition of Find definitions for: dark' adapta"tion Pronunciation: [key] — Ophthalm. Ophthalm. 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. dark Dark Ages TrendingHere are the facts and trivia that people are buzzing about. Did Birds Evolve from Dinosaurs? The Twelve Dancing Princesses Current Events This Week: January 2023 African Americans by the Numbers Andersen's Fairy Tales: Contents The Celtic Twilight: A Teller of Tales ✖ Related Content Daily Word Quiz: minatory Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language