I bought a pair in Eylul, Fethiye, a year ago. My prescription is complicated, but the resulting eye test and glasses are superb, in lightweight plastic. In spite of the complex prescription, they were ready in a week, very impressive.
The price is about the same as in Specsavers. In the UK, I bought another 2 pairs - BOGOF - while the frame choice was much larger, the actual lenses took over 2 weeks to produce, are made of glass as they couldn't get the plastic, and are so heavy. I compared the two sets, and find the eyesight better in the Turkish ones, and comfort much better, though the frames on the English ones were nicer. Swings and roundabouts, but if you are not too bothered about style, I'd say go for the Turkish glasses.