Base Curve: 8. Serengeti Polar PhD lenses deliver clearly superior eyewear for the ultimate journey, featuring the very latest in polarization, photochromic technologies, exclusive hues and high-definition benefits that are near-glass in clarity. Our Polar PhD lens is so revolutionary; it received the coveted international Silmo d'Or award in the lens category for innovation and performance – a first for a sunglass manufacturer. The amber-colored Drivers lens is particularly well suited to driving. That's because it enhances colors and contrast, lightening and darkening for optimal light transmission in any condition. The lens is also engineered to reduce eyestrain and fatigue.