Here's what other sites are saying:
The Spy Diablo Sunglasses use Scoop Technology venting to reduce any chances of fogging, even if you're sweating like crazy in blazing hot downtown temps or a fiery cave. Thanks to a low-profile design and wraparound shape, these Spy sunglasses have a close, secure fit on medium-size faces. The Diablo Sunglasses also provide 100% UV protection. We have no test data on how well they do when you're staring into fire for all of eternity, but we'd imagine they do pretty well.