A perfect complement to the Touchstone, the Backdrop incorporates the same great features like stainless steel spring hinges and Megol contact surfaces at the nose and temple tips. Sharp styling and thoughtful detailing, showcase a medium coverage lens profile with unmatched optical clarity. Stainless Steel Spring Hinges. 8 Base Lens Curvature. Frame Measurements 61-16-135. ChromaPop By blocking specific color wave intersections as they pass through the lens, ChromaPop is able to eliminate color confusion, so your brain is recognizing true color, faster. ChromaPop optimizes color and increases clarity, enabling you to see the outside world with an unparalleled level of vibrance. Techlite Polarized Glass Lenses Techlite Polarized Glass lenses produce clarity, optical precision, and glare reduction beyond all expectations. Provides precise vision that only glass can offer. TPT (Tapered Lens Technology) corrects light distortion for true optical clarity. 99.9% polarized filters and tint shifting photochromic technologies. 12 times more scratch resistant than plastic lenses, and 20% lighter than standard glass lenses. Repels moisture, grease, and grime. Vacuum applied Anti-Reflective coating on the back side of the lens eliminates sidelight reflections. Evolve Frame Material We incorporate the revolutionary, Rilsan#&174; Clear material into what has become the largest eco-friendly sunglass collection in the world. This material allows us to create lightweight, durable frames, that are over 53% bio-based. Rilsan® Clear is derived from the renewable, non-genetically modified castor plant. Evolve frames are flexible, lightweight, highly elastic, remarkably tough, and have excellent chemical resistance. Most importantly, this material is not petroleum based.