oculus vs compound eye

oculus and compound eye both are nouns.

Word	Noun	Adjective	Verb	Adverb
oculus	Yes	No	No	No
compound eye	Yes	No	No	No

As nouns, compound eye is a hyponym of oculus; that is, compound eye is a word with a more specific, narrower meaning than oculus:

oculus: the organ of sight
compound eye: in insects and some crustaceans: composed of many light-sensitive elements each forming a portion of an image

Other hyponyms of oculus include naked eye, peeper, oculus dexter, OD, oculus sinister, OS, ocellus, simple eye, stemma.

oculus (noun)	compound eye (noun)
the organ of sight	in insects and some crustaceans: composed of many light-sensitive elements each forming a portion of an image