eye vs ocellus

eye and ocellus both are nouns.

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

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

eye (noun)	ocellus (noun)
a small hole or loop (as in a needle)	an eyelike marking (as on the wings of some butterflies); usually a spot of color inside a ring of another color
the organ of sight	an eye having a single lens
good discernment (either visually or as if visually)
attention to what is seen
an area that is approximately central within some larger region

eye (verb)	ocellus (verb)
look at