Shimano S21X Sunglasses. Treat your eyes to a pair of high performance eyewear in Shimano's CE S21X sunglasses. The S21X glasses feature Shimano's Brown Silver Mirror lens which is ideal for riding in clear weather as they cut out blue light and ensure natural vision. Additionally, this lens hue provides higher contrast and allow easier perception of distance. The lenses themselves sport anti fog and anti scratch treatments while the TPE temple tips ensure these glasses stay perfectly placed. Also, their frames are constructed of Grilamid TR90 nylon to ensure they're lightweight, strong, and durable.