I've been attending a hospital eye clinic for over 30 years, and wearing glasses for 70 years. I have had 2 cataract ops, plus laser surgery, with more of the latter pending, and been using drops for ages too, . From one lot of drops once a day I've gone to 2 lots of drops - the latter having to be used 3 times a day
So I have a lot of experience with opticians!! I know for sure that the Boots chain have the machine someone mentioned too - can't remember its name, but I think all opticians should have one by now. It's sort of like an eye Xray !
The problem with these chains is that it's not the name that counts, but the quality of the opticians they employ. For years I went to an independent optician recommended to me , who was great. Sadly he died, and I went to another independent optician recommended by another friend and he was good, but his prices kept getting higher and higher with no real justification that I could see.
So I ended up at one of these chains (SS) and got a really poor deal - had to go back 3 times before my new specs were reasonably OK. If I'd seen someone else in the practice maybe it would have been a different story.
I would strongly suggest that you ask friends for recommendations of a specific optician whether they're from a chain, or independent.