I remember these glasses from the 80's (without the cool styling of course).  They are VERY well made and bottom line is...they work.  They cut the "ultra" bright light out and make it easier to see.  I also notice that I don't squint as much with these on, which prevents frown lines from forming....may be a buying point for the more image concience person.  These are the perfect sunny day glasses.  I guess that's why they're called sunglasses....hmmm...go figure.