Sorry may have given the wrong impression on corrective surgery. The RAF will not accept anyone who has had it done before they enter (as far as I know), hence the corneal mapping.
But I talked to the nice optometrist at Cranwell (and Doctors at Med Wing, Henlow) and they said the RAF was looking into providing corrective surgery (like Boots the Opticians) in the near to medium future for aircrew.
Hope that clears up my earlier post.
MT