Noun
tritanopia (countable and uncountable, plural tritanopias)
A form of color blindness in which the retina is deficient in or lacks cone cells containing opsins that respond to the color blue, resulting in an inability to distinguish blue from green.
Color blindness involving the inactivation of the short-wavelength sensitive cone system (whose absorption spectrum peaks in the bluish-violet) is called tritanopia or, loosely, blue–yellow color blindness. Source: Internet
People who have, for instance, both protanopia and tritanopia are considered to have cone monochromacy. Source: Internet