Tifosi Optics is a Georgia-based company that makes sunglasses made for sporting use. The Tifosi name is probably best known in cycling circles, where the company's shades are praised by bike racers. Tifosi (which is Italian for "sports enthusiast") has made a push into the golf market in recent years, even developing lenses that are designed specifically for the sport.
Tifosi has 14 different types of lenses available, and they sell golf-specific version of their frames that come with three sets of lenses that are best suited for most golf conditions. I took three different frame styles - the Kilo, Q3, and Stelvio models - out on the course with me and gave them a thorough test with all three lens types.