I certainly wouldn't fly with polarized glasses, as they can - and do - make panel instruments and GPS units unreadable, never mind the fancy colours you can get looking through the perspex. In addition,
AFAIK (don't have reference for it , though), they are not even legal in FAA land.
Agree with the 2-4-1 deals at the high street chains. Work a treat.
It gets a bit trickier if you need bifocals. If you have these made, the opticians are too used to ordering them for drivers (of cars, that is), with a near-vision inset that's loo low and not wide enough. I've got a pair and it took 3 or 4 attempts to get them right. Make sure you explain clearly what they are for and where (i.e. how high) exactly you want the near-vision insert to sit.