Originally Posted by
leob1
It's not light that makes them turn dark, it's UV. So they can(do) turn dark on cloudy days, too. And if you are on a light surface, like the beach, snow, or a concrete road, the reflected UV will make them turn as dark as a bright sunny day. Sometime they may get a bit too dark, and you can lose details, like a low hanging branch, or road debris. I try not to wear mine on cloudy days, if I remember to switch, for this reason.
Of course these are just my experience, others may have had no issues.
Very true. I knew that it was the UV that caused the tinting to occur(one reason they don't tint in a car...the glass blocks the UV). I use sunglasses more than some people. I have light blue eyes and thus I'm a bit more sensitive to bright light than people with darker colored pupils.
Not that this has anything to do with blue or light colored eyes, but I also have very good night vision. When the sky is clear enough, I can still see all the stars in the constellation Pleiades, all seven. My wife can't and many others I know can't.