– Ventilation gap in upper outside of lens (Prevents fogging).
– TR90 frame has polycarbonate polarized lenses
– Hydrophobic clear coat to repel water, oil, and dust
– Protects against 100% of harmful UV rays
– Meets ANSI Z80.3 standards for optical clarity and resistance
– Optimum use: Running
Test Conditions : Road and Trail
Miles : Over 20 miles
Tasty? YES! They come with interchangeable lens which I have yet to try, but bottom line the provide good eye cover, dark lenses to protect from glaring sunlight, and do not fog up during a long hard run. I am extremely pleased with them. And if you poke around the Internet you can definitely find them for a good price. Beyond pure function they also have a rubber like coating on the arms that hold them in place even under extreme sweat soaked conditions. These are my primary go to sunglasses for sunny day runs.
(Yes, it was a hot muggy day out when shot the picture above.)
Second Opinion: From iRunFar.com (Slightly different model)