Visual purple
Visual Vis"u*al, a. [L. visualis, from visus a seeing, sight: cf. F. visuel. See {Vision}.] 1. Of or pertaining to sight; used in sight; serving as the instrument of seeing; as, the visual nerve. [1913 Webster]

The air, Nowhere so clear, sharpened his visual ray. --Milton. [1913 Webster]

2. That can be seen; visible. [R.] [1913 Webster]

{Visual angle}. (Opt.) See under {Angle}.

{Visual cone} (Persp.), a cone whose vertex is at the point of sight, or the eye.

{Visual plane}, any plane passing through the point of sight.

{Visual point}, the point at which the visual rays unite; the position of the eye.

{Visual purple} (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}.

{Visual ray}, a line from the eye, or point of sight.

{Visual white} (Physiol.), the final product in the action of light on visual purple. It is reconverted into visual purple by the regenerating action of the choroidal epithelium.

{Visual yellow} (Physiol.), a product intermediate between visual purple and visual white, formed in the photochemical action of light on visual purple. [1913 Webster]


The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • visual purple — n RHODOPSIN * * * see rhodopsin * * * rhodopsin …   Medical dictionary

  • visual purple — n. RHODOPSIN …   English World dictionary

  • visual purple — noun Date: 1878 a photosensitive red or purple pigment in the retinal rods of various vertebrates; especially rhodopsin …   New Collegiate Dictionary

  • visual purple — noun a red photopigment in the retinal rods of vertebrates; dissociates into retinene by light • Syn: ↑rhodopsin, ↑retinal purple • Hypernyms: ↑photopigment • Part Holonyms: ↑rod, ↑rod cell, ↑ …   Useful english dictionary

  • visual purple — See rhodopsin …   Dictionary of molecular biology

  • visual purple — Biochem. rhodopsin. [1895 1900] * * * …   Universalium

  • visual purple — noun The pigment rhodopsin …   Wiktionary

  • visual purple — noun another term for rhodopsin …   English new terms dictionary

  • visual purple — see rhodopsin …   The new mediacal dictionary

  • visual purple — vis′ual pur′ple n. rhodopsin • Etymology: 1895–1900 …   From formal English to slang

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