from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A form of colorblindness characterized by defective perception of red and confusion of red with green or bluish green.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A form of color blindness. Involves a defect in distinguishing between red and green.
from The Century Dictionary and Cyclopedia
- n. In physiology and psychophysics, a word introduced by von Kries to designate the form of red-green color-blindness termed by the Helmholtzian school ‘red-blindness.’
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. dichromacy characterized by lowered sensitivity to long wavelengths of light resulting in an inability to distinguish red and purplish blue
prot(o)- + an- + -opia (from the blindness to red, which is considered the first of the primary colors).(American Heritage® Dictionary of the English Language, Fourth Edition)
The regular color blindness tests (Ishikawa plates) test primarily for red-green (protanopia and deuteranopia), and not for tritanopia.
I dunno .. if you look at the protanopia and deuteranopia pics on the wiki page for