To cut a long story short - I have a prescription which is outside initial class 1 limits but well inside the renewals. Couldn't get a class 1 til JAA came along
. I went for my initial at LGW and the eyes man confirmed the above. He said (based on his examination) that he would pass me. The rest of the medical was fine, so I got a normal class 1 piece of paper.
In the 'limitations' box is 2VDL (needs to wear glasses) and another box, which notes that the class 1 was issued with a deviation. In plain English, this means they bent the rules slightly to give you the certificate! The cert is a normal class 1, with full class 1 rights.
When I renewed for the first time, since my eyes were then within the rules, no deviation required meant that the box disappeared. I now have a normal class 1, just like everyone else except for the 2VDL limit, which will always be there.
No extra cost, no messing about - simple as that.