The eyes were stable pretty much straight away. I never had any complications of any kind and I have been free of corrective lenses for six years now.
How to sway the CAA? I can't be 100% sure. First up if you ask them prior to surgery if they will certify you the answer will probably be no, but you should try anyway. I had the surgery and obatined an FAA Class 1. This entailed getting my surgeon to fill in the appropriate FAA form. This meant that I was able to send the CAA an official surgeons report to the CAA in a format which was relevant to aviation. They invited me along to Gatwick and after some deliberation they agreed to give me the Class 1. This is a very abreviated version of what happened and it wasn't all smooth. Still, I'm living proof that the CAA can be swayed. Have the procedure fully documented, with all your notes and perscriptions prior to LASIK and that will help your case.
Oh, by the way, the only experience that I had before I obatined the Class 1 was glider time. I'm still in my twenties as well.