tritanopiaPronunciation: /ˌtrɪtəˈnəʊpɪə/Definition of tritanopia noun [mass noun] a rare form of colour blindness resulting from insensitivity to blue light, causing confusion of greens and blues. Compare with protanopia.Origin: early 20th century: from trito- 'third' (referring to blue as the third colour in the spectrum) + an-1 'without' + -opiatritanopia in other Oxford dictionaries Definition of tritanopia in the US English dictionary