Or how about prescription glasses with photo sensitive lenses that become sunnies when exposed to sunlight? Sadly, uncool people who wear sunnies don't look cool - they just look like uncool people with sunnies ... http://www.youtube.com/watch?v=vIGPb7-LfjsI don't wear glasses, but when I did some gigs back in the day, I'd wear sunglasses for the first song or two just to look cool. The drummer I jammed with last Tuesday was wearing sunglasses the whole night. Yes, it was inside and it was night. He sure did look cool over there....for a drummer.
Maybe you can wear prescription sunglasses! Way cool!
I have to wear them because I'm blind as a bat otherwise, like Masheanhead. Around -4 dioptres. I tried wearing contacts in my 20s but was not happy with sticking a finger in each eye in the morning.