Michael Holland wrote a review of Oakley M Frame Heater Sunglasses on May 6, 2009
I've had a couple of generations of these, and they rock. My primary use is XC mountain biking, and they've never fallen off (not even close) under some very jarring conditions. The full wrap-around coverage resists the wind, and ensures that whatever you put your face through (bushes and tree branches are not uncommon) your eyes will be protected. It is not hard to scratch polycarbonate lenses, (regardless of brand) but it is really tough to break them. I trust these completely. I also suggest a clear lens so that you can ride after sundown and still have full eye protection.