Young–Helmholtz theory

Young–Helmholtz theory

The Young–Helmholtz theory (proposed in the 19th century by Thomas Young and Hermann von Helmholtz) is a theory of trichromatic color vision – the manner in which the photoreceptors in the eyes of humans and other primates work to enable color vision.

In 1802, Young postulated the existence of three types of photoreceptors (now known as cone cells) in the eye, each of which was sensitive to a particular range of visible light.

Hermann von Helmholtz developed the theory further in 1850: that the three types of cone photoreceptors could be classified as short-preferring (blue), middle-preferring (green), and long-preferring (red), according to their response to the wavelengths of light striking the retina. The relative strengths of the signals detected by the three types of cones are interpreted by the brain as a visible color.

The theory was proved over a century later in a 1983 experiment by Dartnall, Bowmaker, and Mollon, when microspectrophotopic readings of single eye cone cells were obtained. [Eysenck, M. W. and Keane, M. T. (2005) Cognitive Psychology : a student's handbook. Fifth Edition, Psychology Press Ltd (East Sussex).]

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  • Young-Helmholtz theory — Young Helm·holtz theory yəŋ helm .hōlts n a theory in color vision: the eye has three separate elements each of which is stimulated by a different primary color Young Thomas (1773 1829) British physician, physicist, and Egyptologist. Young is… …   Medical dictionary

  • young-helmholtz theory — ˈyəŋˈhel]mˌhōlts, ˈheu̇] noun Usage: usually capitalized Y&H Etymology: Thomas Young died 1829 English physician and physicist and Hermann L. F. von Helmholtz died 1894 German physicist : a theory in color vision: the eye has three separate… …   Useful english dictionary

  • theory — A reasoned explanation of known facts or phenomena that serves as a basis of investigation by which to seek the truth. SEE ALSO: hypothesis, postulate. [G. theoria, a beholding, speculation, t., fr. theoros, a beholder] adsorption t. of narcosis… …   Medical dictionary

  • Young, Thomas — born June 13, 1773, Milverton, Somerset, Eng. died May 10, 1829, London English physicist. Trained as a physician, he practiced medicine at St. George s Hospital (from 1811 until his death) but spent much of his time on scientific research. He… …   Universalium

  • Helmholtz — Hermann L.F. von, German physician, physicist, and physiologist, 1821–1894. See H. axis ligament, H. energy, H. theory of accommodation, H. theory of color vision, H. theory of hearing, H. Gibbs theory, Gibbs H. equation, Young H. theory of color …   Medical dictionary

  • Young — William John, 20th century Australian biochemist. See Harden Y. ester. Thomas, English physician and physicist, 1773–1829. See Y. modulus, Y. rule, Y. Helmholtz theory of color vision. Hugh H., U.S. urologist, 1870–1945. See Y. prostatic tractor …   Medical dictionary

  • Hermann von Helmholtz — Infobox Scientist name = Hermann von Helmholtz |225px image width = 225px caption = Hermann Ludwig Ferdinand von Helmholtz birth date = birth date|1821|8|31|mf=y birth place = Potsdam, Kingdom of Prussia residence = Germany nationality = German… …   Wikipedia

  • Thomas Young (scientist) — Infobox Scientist name = Thomas Young box width = image width = 240px caption = birth date = birth date|df=yes|1773|06|13 birth place = Milverton, Somerset, England death date = death date and age|df=yes|1829|05|10|1773|06|13 death place = London …   Wikipedia

  • Young —   [jʌȖ],    1) Andrew, amerikanischer Politiker, * New Orleans (La.) 12. 3. 1932; kongregationistischer Geistlicher, engagierte sich als Afroamerikaner in der Bürgerrechtsbewegung, in der er den gemäßigten Flügel repräsentierte, besonders für die …   Universal-Lexikon

  • Helmholtz, Hermann von — ▪ German scientist and philosopher Introduction original name  Hermann Ludwig Ferdinand Helmholtz  born Aug. 31, 1821, Potsdam, Prussia [Germany] died Sept. 8, 1894, Charlottenburg, Berlin, Ger.  German scientist and philosopher who made… …   Universalium

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