> But it's still a wrong usage. There is no such thing as "correct" in language, except in Europe where one or two countries have official standards (e.g. Fran

> But it's still a wrong usage. There is no such thing as "correct" in language, except in Europe where one or two countries have official standards (e.g. France). For English there is only colloquial usage and maybe the Oxford English Dictionary (Which 99% of the time agree with each other). Both of them state that "Color-blindness" is the accepted term referring to all conditions related to color deficiency. > People usually don't use both for different meanings. And welcome to English, where we have one word that encompasses any color-deficiencies, and we call that word "color-blindness". It is used as a blanket term for any color-deficiency, including but not exclusive to red-green, yellow-blue, and monochrome vision. I can tell you now, that as a native English speaker, if you were to talk about "color blindness" to another native speaker, they will not assume that you mean Monochromacy specifically. In fact, they are more likely to think that you mean red-green color-blindness, since that is more common than Monochromacy. In any case, it is extremely rare to find usage that matches yours. (Literally. The first reference in the Oxford English Dictionary is to Protanopia, not Monochromacy: https://en.oxforddictionaries.com/definition/colour-blind https://en.oxforddictionaries.com/definition/colour-blind)