glasses vs optical instrument

glasses and optical instrument both are nouns.

Word	Noun	Adjective	Verb	Adverb
glasses	Yes	No	No	No
optical instrument	Yes	No	No	No

As nouns, optical instrument is a hypernym of glasses; that is, optical instrument is a word with a broader meaning than glasses:

glasses: (plural) optical instrument consisting of a frame that holds a pair of lenses for correcting defective vision
optical instrument: an instrument designed to aid vision

glasses (noun)	optical instrument (noun)
(plural) optical instrument consisting of a frame that holds a pair of lenses for correcting defective vision	an instrument designed to aid vision