Makes a certain amount of sense I guess. Out of interest are there any rules governing the use of sunglasses while in the cockpit? I.E. are you allowed to wear them whenever you want, or at anytime except landing and take off? Surely they would have the same effect as CVD contact lenses? I do appreciate with this however that you can always just remove them if you're having trouble seeing things clearly
Just curious really as if there are no guidelines on the use of sunglasses then theoretically a pilot could wear them from gate to gate, and this would surely substantially reduce the wearers colour perception.