I've ben wearing them for about 6 years now.
My first pair from Specsavers were amazing! Brilliant, loved them. But I did pay for the best quality lenses.
Second pair, they had changed the lenses, took three returns to get the prescription right, once they gave me the same lenses as first time, excellent.
Third pair, have been back twice, had my eyes retested, again, they got the prescription wrong, and still can't wear them! I wear them a day or two, then get pains in my eyeballs! I know they are wrong, but not getting anywhere with Specsavers :-( So huge outlay, but no working glasses.
Not sure what to do now, as it's been six months and I still can't wear them :-(
Son had his eyes tested there and had huge trouble with the last pair, took almost a year to sort out (just a normal prescription)
Has had his eyes tested recently and we're wary of getting his glasses there, but other shops make it difficult to know how much
you'll pay

Prices are excellent but ability to supply an acceptable pair of glasses seems to be a lottery