When i did my class 1 medical a couple of years ago (robes were still there, and still too small!!!) I went to the local optician to get eyesight sorted, there's a special form they need to fill out, but it only costs about £25 and i actually got an instant refund of around £50/60 from the CAA so it may be worthwhile doing. Plus it makes they day run a little quicker. Not sure this is standard practise but they seemed more than happy with it.
