When I first left the gray sun deprived upper-ish midwest (Hey SAD isn't a disease it is a CULTURE!) I discovered that I needed sunglasses. I also discovered that I had a sorry tendency to step on, sit on, misplace or otherwise render my sunglasses unusable. As a poor grad student this was not consistent with purchasing good sunglasses.
So for mmphty years I've stuck to my cheap sunglasses until this summer. My MIL gave me a classy pair of grown up sunglasses. What a difference!