These JSDF shades have apparently been endorsed by the Japanese military because they won't fracture even if struck at 170km/h by a 6.5mm-diameter object. Not quite bulletproof, but the picture looks cool.
The Japan Trend Shop also says the 2mm-thick lenses wouldn't shatter, even if a 500g shaft of iron is dropped on them from 1.2m. You know, for those times when you escape the clinches of some evil mastermind at the last minute. I guess I'll give them the benefit of the doubt, but it still kinda sounds like they're just pulling numbers out of the air.