noun (sometimes initial capital letter) Pathology.
color blindness, especially the inability to distinguish red from green.
Origin of daltonism
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
colour blindness, esp the confusion of red and green
Word Origin for daltonism
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
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.