Our Barstow Dalloz replacement lenses are crafted exclusively at the state of the art Christian Dalloz Sunoptics facility located in Saint-Claude, France.For more than 50 years, Dalloz Sunoptics has been driven by the philosophy of transforming new ideas into aesthetically pleasing, high-performance technical lenses. The cylindrical shape of the Dalloz lens shifts visual distortions to the periphery, where the lens is edged, creating flawless clarity and excellent peripheral vision without any blurred zones. The durable lens works in union with the minimal frame design of the Barstow to offer superior visibility in any conditions. Smoke Lens: Filter Category: 1.Light Transmission: 45%±2%. Silver Lens: Filter Category: 2.Light Transmission: 25%±5%. Bronze Lens: Filter Category: 1.Light Transmission: 27%±3%. Clear Lens: Filter Category: 0.Light Transmission: 88-92%.