Spectrum KALL Sunglasses Black - Grey Kall offers wide protection to enhance the periphery for an optimized experience. Built for extended active use, whether running, cycling or climbing. The gray Zeiss base lens is ideal for extended use during bright and sunny days. This lens provides visual protection from strong reflections and offer the greatest visual comfort and natural perception without color distortion. The Zeiss Violet Base contrast lens is ideal for sunny to cloudy days and provide the best visual contrast, brilliance of color and image definition in a mountain or forest environment.