- a defect of vision in which the retina fails to respond to red or green.
Origin of protanopia
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- a form of colour blindness characterized by a tendency to confuse reds and greens and by a loss of sensitivity to red light
C20: New Latin, from proto- + an- + -opia
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
- A form of colorblindness characterized by defective perception of red and confusion of red with green or bluish green.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.