No problem reading my Garmin in polarized lenses. Still, I mostly used non-polarized photochromatic lenses these days and ride a lot in the dark or in shifting light conditions. Also, I've found that polarized lenses are often too dark for me while riding. Many sunglasses have too much light blockage for me, which can make it hard to see if the lenses are sweaty and I'm riding in mixed light/shade. This is another benefit of photochromatic lenses for me: they don't get as dark as most traditional sunglasses.