Sunglasses
If it's a bright, clear day outside, you may instinctively reach for your sunglasses when you head for the door. And you probably do it without much thought.
A pair of sunglasses seems so simple -- it's two pieces of tinted glass or plastic in some sort of plastic or metal frame. How much more straightforward can something get? It turns out that there are many different things you can do with two pieces of glass, and these things can have a big effect on you when you use the lenses. There really is a difference between the various sunglasses you'll find out there.
