sunglass vs converging lens

sunglass and converging lens both are nouns.

Word	Noun	Adjective	Verb	Adverb
sunglass	Yes	No	No	No
converging lens	Yes	No	No	No

As nouns, converging lens is a hypernym of sunglass; that is, converging lens is a word with a broader meaning than sunglass:

sunglass: a convex lens that focuses the rays of the sun; used to start a fire
converging lens: lens such that a beam of light passing through it is brought to a point or focus

Other hypernyms of sunglass include convex lens.

sunglass (noun)	converging lens (noun)
a convex lens that focuses the rays of the sun; used to start a fire	lens such that a beam of light passing through it is brought to a point or focus