optician vs trained worker

optician and trained worker both are nouns.

Word	Noun	Adjective	Verb	Adverb
optician	Yes	No	No	No
trained worker	Yes	No	No	No

As nouns, trained worker is a hypernym of optician; that is, trained worker is a word with a broader meaning than optician:

Other hypernyms of optician include skilled worker, skilled workman.

optician (noun)	trained worker (noun)
a worker who makes glasses for remedying defects of vision	a worker who has acquired special skills