OD vs eye

OD and eye both are nouns.

Word	Noun	Adjective	Verb	Adverb
OD	Yes	No	No	No
eye	Yes	No	Yes	No

As nouns, eye is a hypernym of OD; that is, eye is a word with a broader meaning than OD:

Other hypernyms of OD include oculus, optic.

OD (noun)	eye (noun)
the right eye	a small hole or loop (as in a needle)
a doctor's degree in optometry	the organ of sight
	good discernment (either visually or as if visually)
	attention to what is seen
	an area that is approximately central within some larger region

OD (verb)	eye (verb)
	look at