This lens type material was developed by the aerospace industry for use in helmet visors worn by astronauts. It is also widely used in bulletproof windows, airplane windows, and riot police shields. This material is 10 times more impact-resistant than other plastics, and exceeds the resistance requirements by over 40 times. Spyder Resillens is lighter and is about 20% thinner than standard plastic or glass, so they don’t constantly slide down on the nose. The material is a natural UV filter blocking 100% of the sun’s damaging UV rays without the need for special lens coatings. This is particularly important for outdoors sports, because researchers believe that overexposure to UV rays over the years has been associated with and other eye problems.