red-blindness red blindness • red blood · · · Info · Definitions · Synonyms · Characters · · red-blindness · · Text Common · · Latin · · Scripts 13 · · Length 3 · · Syllables Definitions · · · (noun) dichromacy characterized by lowered sensitivity to long wavelengths of light resulting in an inability to distinguish red and purplish blue. Synonyms: protanopia. · · Noun Definition 1 Synonyms · · · protanopia · · Synonym 1 Characters · · - hyphen-minus U+002D b latin small letter b U+0062 d latin small letter d U+0064 e latin small letter e U+0065 i latin small letter i U+0069 l latin small letter l U+006C n latin small letter n U+006E r latin small letter r U+0072 s latin small letter s U+0073