monochromatic vision vs monochromia

monochromatic vision and monochromia both are nouns.

Word	Noun	Adjective	Verb	Adverb
monochromatic vision	Yes	No	No	No
monochromia	Yes	No	No	No

As nouns, monochromatic vision and monochromia are synonyms defined as:

monochromatic vision and monochromia: complete color blindness; colors can be differentiated only on the basis of brightness

Other synonyms of monochromatic vision include monochromacy, monochromasy, monochromatism.

monochromatic vision (noun)	monochromia (noun)
complete color blindness; colors can be differentiated only on the basis of brightness	complete color blindness; colors can be differentiated only on the basis of brightness