I use Specsavers these days, but I don't think there's much to choose between any of them. Whichever gives you a decent deal I suppose. As SD points out, you can take your prescription to any cheap web trader, too.
I go to an independent optician these days.Not keen on the hard sell in Specsavers.All the time I went there they never picked up on a mole behind my eye but the independent chap did and sent me to the eye clinic .Luckily it was nothing untoward.His prices are no dearer than Specsavers,in fact it was a bit cheaper.If you call 400 notes cheap,lol..but he did chuck in some sunglasses.
I wish I could get cheaper specs but my prescription is much too complicated for the on line retailers.
They both seem to use lots of locum opthalmologists, and with specsavers the dispensing opticians seem to be on commission, which leads to the hard sell. Like Shaney I have wonky eyes, and currently I'm using a nearby Asda with great satisfaction. Unfortunately it seems that outside the small independents, skills vary enormously among what is essentially a posting that many pass through on their way to their own practice.
Specsavers isn't a "chain" like many....they work similarly to franchises, and each branch is "owned" by it's senior person/people. Consequently, service can vary greatly between branches.
I've never had the "hard sell" at my branch (I was told that I didn't need a new prescription on the last two sight tests) and was referred to the local hospital when they found a problem with my right retina. So, I'm more than happy with Specsavers.
My friendly local optician tells me he will recommend glasses only when they are absolutely essential. Boots wanted to flog their specs at every exam. Meanwhile poundland specials great for threading needles etc.