I personally buy blue block polarized sunglasses, they give me the clearest glare free view of my sourroundings. And yes they do make screens of speedometers dark, but I dont continually look at mine. If I really need to look at it, I just raise my glasses and glance at it. The safety of the blue block polarized sunglasses it the over ridding thing. My need for safety far over rides the need to read the speedometer.