color blindness

proportion and types in the world

Color blindness, or color vision deficiency, is the inability or decreased ability to see color, or perceive color differences, under normal lighting conditions (from wikipedia [1]).

Most color blind people are able to see colors - they have only a biased perception of some colors [2]. There are 4 main kinds of color blindness:

• deuteranomalous (6% of males) is the most common form of color blindness; deuteranomalous persons are "green weak".
• protanopes (1% of males), deuteranopes (1% of males) and protanomalous (1% of males) are unable to distinguish between colors in the green–yellow–red section of the spectrum

If you are not colorblind, you may still discover this experience thanks to several websites, including [4].

Ironically, most color blind people will have difficulties with this graph on color-blind people. Good practices to help the numerous colorblind people are to always use symbols along with colors; also the use of opposite colors will help most of them.