[at-l] Checking for polarized lenses

[askowronek@mindspring.com (Amy)]

Rob wrote:

> You can check to see if sunglasses have polarized lenses. Take 2 pair
> off the rack. put one lense on top of the other. Rotate the top pair,
> keeping the lenses on top of each other. If the lenses are polarized,
> you'll be able to block 100% of the light coming through. -Rob



I was just thinking about that.  My dad is a physicist, and he
brought me home a couple of chunks of polarized plastic when I
was a kid.  I spent hours playing with them.. and probably still
would if I could find them.

Could someone remind me what the advantage of polarized lenses is?
Is it just that you cut down on the number of photons entering
your eyes, or is there some other benefit?

-amy, once a physics major