I've recently applied FogCity HyperOptiks Light Reactive on my Shark RSR helmet, it gives me just the right amount of "shade" on those sunny days. Of course when it's extremely bright outdoors, this doesn't cut it but then again if it's that bright chances are it's also that much hotter. I opted for the light green version that turns blue when exposed to sunlight. Underneath I also wear prescription glasses that has Transition lenses. I like the results that I get with the FogCity HyperOptiks, not too dark and lets enough light through, especially when it's dusk or a night ride. No need to bring extra lenses.