Well I guess I won't have my own for next Sunday. I have an old spare pair of glasses that are small framedt so I'll wear them. Hopefully thy won't t be quite as painfull under the hire ones.
I'll send out some emails and see what the places have to say.
My optician is very good and will probably come up with something. I'm optimistic that they will be able to glaze the inserts as they do some very thin lenses, but I'm sure that will will at a price premium!!
Thanks again