The THEORY'S rimless interchangeable lens system creates a sleek and subtle design allowing unobstructed peripheral view perfect for the running trail, golf course, or weekend ride. Smith's Interchangeable lens system utilizes distortion-free, 9 base lenses to provide precise optical clarity and maximize coverage while minimizing peripheral exposure to sun, wind, and glare. With over a dozen replacement lens tints to choose from, the Smith Interchangeable series provides versatility across the full spectrum of light conditions and sport eyewear enhancements.