I used to fly with a pair of metal framed Ray-Bans that had a polarising element, without any problems - until we fitted a new KX-155 nav/com; with the Ray-bans on, the unit looked as if it was switched off and it took a stomach-clenching couple of minutes for me to clock what the problem was....DOH!
I now fly with some trad 50's Ray-bans with the arms bent over a hot kettle (so they lie flat against my head with the head-set on) which, imho, are the canines-clackers.