In reply to CurlyStevo:
> For Scottish winter I've never taken or needed glacier glasses.
I've climbed in glacier glasses on occasion (when it's very sunny), but realistically any sunglasses will do. Glacier glasses are practical though if you happen to have a pair, as the blocked in side pieces help protect the eyes against spindrift.
Cat 3 isn't too dark when it's sunny in Scotland, but unfortunately that's rarely the case!