Made for the creators, these lenses are specifically designed for glass artists. We're very proud to say our family of these artists has come to include some of the most profound, influential, and amazing glass artists in the world. Made in America by Aura Visual Concepts, our lenses are the highest quality glass working lenses available. These lenses provide top-notch protection against IR radiation and minimize visible sodium flare. Split lenses and single vision prescription are available as well. We use TR90 for all of our new didymium/boro frames. There is a lifetime guarantee on all products to be replaced.