Photochromic technology designed to constantly adjust to changing light conditions * Spectral Control technology gives you stunning, high-definition contrast and color enhancement * Polarization technology engineered to eliminate distracting glare * Using only the highest quality injected nylon for superior durability, exceptionally light, flexible and comfortable * All Serengeti lenses offer the latest in photochromic technology, which constantly lightens and darkens throughout the day to ensure you see every detail.