. DISTRICT VISION put two years of research and development into its latest line of eyewear, borrowing know-how from top athletes and engineers around the world. , These 'Nagata Speed Blade' sunglasses are constructed with lightweight titanium-core nylon frames for durability, Hypoallergenic adjustable nose pads keep them comfortable and secure, Polarized D+ lenses are shatterproof, as well as oiland water-repellent