monochromia vs monochromacy

monochromia and monochromacy both are nouns.

Word	Noun	Adjective	Verb	Adverb
monochromia	Yes	No	No	No
monochromacy	Yes	No	No	No

As nouns, monochromia and monochromacy are synonyms defined as:

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

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

monochromia (noun)	monochromacy (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