I have an ongoing concern with glaucauma (spillong?).  Went to Optima Salas Tortosa, and asked for an ad hoc test; they fell over backwards to comply, and didn't charge me a cent..... they said to come back every 9-12 months, off the street, for a free check up.   On the other hand, with the same shop, I paid a lot of money for a set of glasses some years back and they fell apart well within the guarantee period. I have never had that with any UK supplier, be it small town independent or Specsavers - type high street shops.  Personally, I would not spend  anything more than 200 euros here at an opticians.