Bloc eyewear shadow black sunglasses 3 interchangeable lens description the ultra modern and lightweight shadow is a vital part of any kit bag providing demanding athletes the ultimate in performance and protection perfect for skiing cycling and shooting with maximum peripheral vision conforms to eu standard bs en 1836 2005 a12007 lens 3 interchangeable lens system 3 interchangeable lenses let you adapt to all sports and all weather conditions the three lenses supplied are