Just to add, you have spent the last N years, especially if you are aircrew, lying to the medics that you eyesight and hearing are perfect and you are fully fit. You are a fully paid up member of the anti-hyperchondriac brigade. Now you need to convince the docs that you are damn near a wreck.
The longer you leave it between exit and application the more wriggle room th edocs have for saying it was a post-service problem.