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[dawl-tn-iz-uh m] /ˈdɔl tnˌɪz əm/
noun, (sometimes initial capital letter) Pathology.
color blindness, especially the inability to distinguish red from green.
Origin of daltonism
1835-45; J. Dalton + -ism
Related forms
[dawl-ton-ik] /dɔlˈtɒn ɪk/ (Show IPA),
adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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Examples from the Web for daltonism
Historical Examples
  • Certain authorities on art are said to regard the great Montalbanais as a victim of daltonism—in other words, colour-blind!

    In the Heart of Vosges Matilda Betham-Edwards
  • daltonism, dal′ton-izm, n. colour-blindness: inability to distinguish certain colours.

  • An interesting example is the common type of color blindness known as daltonism.

    Physiology Ernest G. Martin
  • Colour-blindness or daltonism has been recorded (Horner) through the males only of seven generations.

    The Making of Species Douglas Dewar
  • The diseases known as daltonism or colour-blindness, and hmophilia or the bleeding disease, are certainly hereditary.

    Parenthood and Race Culture Caleb Williams Saleeby
British Dictionary definitions for daltonism


colour blindness, esp the confusion of red and green
Derived Forms
daltonic (dɔːlˈtɒnɪk) adjective
Word Origin
C19: from French daltonisme, after John Dalton
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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daltonism in Medicine

daltonism dal·ton·ism (dôl'tə-nĭz'əm)
An inherited defect in the perception of red and green; red-green colorblindness.

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