I noticed from an earlier post that someone was concerned about the Prison Service allowing people to join after certain surgeries. The latest standing from the Armed Forces (who use a similar, if not more demanding standard, which is also similar to the requirements of the Police Service), is that for corrective refraction the following methods are now considered suitable prior to entry on a case-by-case basis:

PRK, LASEK, LASIK, Intra Corneal Rings or Segments.

Entry is not permitted for those who have had Radial Keratotomy or Astigmatic Keratotomy.

Importantly, these are generally considered "OK" - but advice should be taken prior to surgery being carried out if you are serving, or plan to serve, in this sort of occupation.