g10,
If you have eye tests from previous years then you may be able to prove stability and beat the system that way.
More importantly however, IT IS NOT CAST IN STONE. The CAA can bend the rules if they wish and I know of people who like yourself (and myself for that matter) are just outside the limits but have been given their class 1.
All it takes is determination. For God's sake don't give up - there must be hundreds (or more) people out there who would have been cracking pilots but for the fact they gave up when the CAA pronounced they didn't meet the standard.
Don't let the Bas@#&ds grind you down.
If you keep pestering them and make their life hell they will eventually bend and let you have the class 1.
I'm not saying this is the case for any medical ailment but in instances like your's where you are so very close to the limit (and actually meet the renewal criteria) then it's entirely possible.
Take a look at some of Mr Magoos previous posts (I'm pretty sure he was in a similar position to yourself - and he's got his class 1 now!)
Good Luck
(p.s. please let the forum know how you get on)