Simple straightforward prescription, probably Specsavers etc. are fine
Any complex condition or history, as I have, then I’d be looking at a well recommended local optician. In my case my GP was a great help, pointing me in the right direction.
After Boots took over my local D&A the service in all respects was utterly appalling.
Eye test was around £26, new reading specs £150 for entirely presentable 1/2 frame style. Could easily have doubled that if I’d felt so inclined.