Hi ItsAWingThing,
Sorry I can't speak for the RAF, but here in Australia the RAAF (and all the military services) have a total ban on anyone using Ortho-K for aircrew of any type, and I think for any ADF personal, although I'm not 100% sure on that. The USAF I believe has no such ban though.
Thankfully down here the eyesight myopia requirement is slightly leaner (6/12 uncorrected, 6/6 corrected) and I managed to scrape through the eyesight requirement.
Formski