iridotomy vs eye operation

iridotomy and eye operation both are nouns.

Word	Noun	Adjective	Verb	Adverb
iridotomy	Yes	No	No	No
eye operation	Yes	No	No	No

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

iridotomy: a surgical procedure that makes an incision in the iris of the eye in order to enlarge the pupil or to treat closed-angle glaucoma
eye operation: any surgical procedure involving the eyes

Other hypernyms of iridotomy include eye surgery.

iridotomy (noun)	eye operation (noun)
a surgical procedure that makes an incision in the iris of the eye in order to enlarge the pupil or to treat closed-angle glaucoma	any surgical procedure involving the eyes