Well the RAF have access to your medical reports when you go for a trade, remuster, or get promotion. or a new offer of service, so i think it would be a bit silly to cover it up. i think honesty is the best policy.
For those who keep PM me about glasses and the respirator - you do not wear glasses at all, or put them on during your decontamination drills! you keep them off, or get lenses for your mask.