I would just like to say that I had a great optical experience at Green Lanes Eyecare Centre, 20 Grand Parade, N4 1LA (next to Iceland).
I had been to Specsavers on Friday for an eye test and had my prescription. Green Lanes Eyecare were very friendly and welcoming. They were fine about me using some old frames so just needing new lenses, although I thought they had a very good range and will change frames there in the future. They also suggested another eye test (free) just to make sure my previous eye test was correct. There was a slight discrepancy, so again I was very grateful for their fastidiousness.