Polarized lenses are not that great as you can't see some LCD instruments
This caught me out in an R22.
Preparing to transit East Midlands airspace and had been asked to Squawk XXXX. Got close to the zone with no clearance and the Transponder still wasn't flashing to indicate that SSR was picking me up. Told the pax that we may need to go round - couldn't get higher due cloud base and thought SSR couldn't see me at my altitude.
East Mids came back with clearance just in time (they were busy) - turns out the Transponder had been flashing for 5 minutes but I couldn't see it through the polarized lenses.
RC