dark adaptation

dark adaptation
dark adaptation .därk- n the phenomena including dilation of the pupil, increase in retinal sensitivity, shift of the region of maximum luminosity toward the blue, and regeneration of rhodopsin by which the eye adapts to conditions of reduced illumination compare LIGHT ADAPTATION
dark-adapt·ed 'därk-ə-.dap-təd adj

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the changes that take place in the retina and pupil of the eye enabling vision in very dim light. Dark adaptation involves activation of the rod - the cells of the retina that function best in dim light - and the reflex enlargement of the pupil (see pupillary reflex). Compare light adaptation.

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the adaptation of the eye to vision in the dark or in reduced illumination (night vision), with build-up of rhodopsin in the retinal rods; called also scotopic a.

Medical dictionary. 2011.

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  • dark adaptation — n. the adaptation of the eye to vision in the dark by dilation of the pupil, increased sensitivity of the retina, etc. dark adapted adj …   English World dictionary

  • dark adaptation — The process by which the iris and the retina of the eye adjust to allow maximum vision in dim illumination following exposure of the eye to a relatively brighter illumination. In darkness, vision becomes more sensitive to light, provided a person …   Aviation dictionary

  • dark adaptation — the changes that take place in the retina and pupil of the eye enabling vision in very dim light. Dark adaptation involves activation of the rods – the cells of the retina that function best in dim light – and the reflex enlargement of the pupil… …   The new mediacal dictionary

  • dark adaptation — prisitaikymas prie tamsos statusas T sritis fizika atitikmenys: angl. dark adaptation vok. Dunkeladaptation, f rus. темновая адаптация, f pranc. adaptation à l’obscurité, f …   Fizikos terminų žodynas

  • Dark adaptation threshold — (DAT) is a vision test that measures the adjustment of the eye occurring under low levels of illumination. When light enters the eye, it ultimately reaches the rods and cones, which are two types of cells in the retina. Rods handle vision in low… …   Wikipedia

  • dark adaptation — dark adapted, adj. 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… …   Universalium

  • dark adaptation — dark′ adapta tion n. oph the reflex adjustment of the eye to dim light or darkness, consisting of a dilation of the pupil, an increase in the number of functioning rods, and a decrease in the number of functioning cones • Etymology: 1905–10 dark′ …   From formal English to slang

  • dark adaptation — /ˈdak ˌædæpteɪʃən/ (say dahk .adaptayshuhn) noun the reflex response of the eye to a diminution of light, comprising the dilation of the iris and an increase in the number of functioning rods with a corresponding decrease in the number of… …  

  • dark adaptation —    A change in the retina of the eye sensitizing it to dim light (the eye “becomes accustomed to the dark”) [25].    Compare light adaptation …   Lexicon of Cave and Karst Terminology

  • dark adaptation — noun the process of adjusting the eyes to low levels of illumination; cones adapt first; rods continue to adapt for up to four hours • Hypernyms: ↑adaptation …   Useful english dictionary

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