eye vs stemma

eye and stemma both are nouns.

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

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

eye (noun)	stemma (noun)
a small hole or loop (as in a needle)	an eye having a single lens
the organ of sight	the hereditary derivation of an individual
good discernment (either visually or as if visually)	a tree diagram showing a reconstruction of the transmission of manuscripts of a literary work
attention to what is seen
an area that is approximately central within some larger region

eye (verb)	stemma (verb)
look at