Our philosophy hinges on style paired with premium materials and quality construction. Built for tough, everyday wear. With a respect for classic, timeless styles and attention to trends, Bertha is guaranteed to make you stand out. High-Quality TR90 Frame; TR90 is made with a Swiss technology to be super flexible, durable and lightweight. Multi-Layer TAC Polarized Lenses Eliminates 100% of UVA/UVB Harmful Blue Light and Glare High-Quality Lightweight Acetate Arms Standard Stainless Steel Hinges Scratch and Impact Resistant