Opticians do them, and so does Boots. Though I suppose Boots contains an optician's, so I perhaps ought to say 'opticians, including Boots, do them'. Though I have a feeling they're not only in the optician bit of Boots

(Can that apostrophe arrangement possibly be correct?)

Um.

I'll shut up now.

I would probably know this myself if I'd got round to going to an optician at any point in the last five years :-) Thanks.