If Elvis is a cyclist, he's wearing the Giro Instigator as we speak. They're boxy, just like The King prefers, but they've got more than enough performance to be ridden with. A good look at these will tell you as much. Straight on, they almost seem like a two-dimensional prescription sunglass, possibly worn by the maniac in Repo Man. From the side, they're swept back, like they've been shaped by the wind. .

The frame is designed to fit a human head that is wearing a helmet. This means that the temples hit neither the straps nor the secondary retention system. That there is no binding means the glasses are easier to get on, get off, and have them stay in place. With rubber temple tips and nosepiece, these glasses will stay put. With Wind Tunnel Technology vents, you won't have a need to remove them, even on the muggiest of climbs.

The lens also curves a good bit more than the regular single-lens sportglass. Giro calls it True Sight, which is just a trademarked way of saying that the range of clear, accurate, non-distorted vision is a total of 60 degrees, 30 each from center, which is much more than the average sport sunglass can say for itself.

Every Giro Lens comes with a number after the shade. This is the Visible Light Transmission (VLT) index. The lower the number, the darker the lens. Giro lenses range from 82 for clear to 12 for their polarized lens. The polarized lens has a "z" after the VLT indicating that it is Zeiss Certified. Carl Zeiss Vision specializes in incredibly distortion-free lenses. Giro hammered out an exclusive arrangement Zeiss and the lenses are not only designed but manufactured to the highest standards.

All Giro sunglasses come with a Dura Clean coating. This is a two-component coat on top of the lens which helps repel water, oil, and fingerprints on one level, and helps prevent lens scratching on another.

The Giro Instigator has a two-lens full-frame sunglass. The frame is made of Grilamid. The lenses are 8-Base True Sight polycarbonate. The Frame/Lens Color Combinations are: Bronze Fade/Brown (16), Gloss Black/Grey (20) and Gloss White/Grey (20). The lenses are not interchangeable. The glasses ship in a box that contains a soft cloth carrying case that is also ideal for lens cleaning.