They certainly use a corneal topographer at RAF Cranwell for testing the RAF hopefuls.
They do not have a CT yet at Gatwick. However, what happens if you do not admit to having refractive surgery upfront and two years down the line they purchase a CT system and they subsequently tested you?
PRK is less instantly obvious than LASIK as there is no corneal flap. CT would highlight any laser treatment instantly, as would pachymetry (corneal thickness). However, an average optometrist would be less likely to spot anything when compared to an average ophthalmic consultant.
regards
------------------
Half man, Half jalfrezi.