Thanks guys - I will get on the phone to my optometrist and get the most recent figures he has. I'm quite annoyed, mainly because if people can put down "unknown" and still get through to the medical, I don't see why you can be rejected automatically on the somewhat insubstantial basis of what you as the applicant (not optometrist) puts down. Hypothetically, someone with absolutely terrible eyesight could get through on the basis of writing "unknown". Hopefully you can see what I'm going on about!
I'm also quite surprised as I've passed RAF & RN medicals for the same job fine, and I would have thought they would be more stringent than NATS, but clearly not.
pugwash - Unfortunately I'm only 18, so the "over 26" card is one less leg for me stand on! But I'll let you know how mine goes. Best of luck with yours!
Cheers