Gunnar Optiks Computer Eyewear - Metropole Onyx Frame Acustom blended proprietary polymer, which beats out polycarbonate on the toughness scale Custom designed to provide focusing power that eases eye strain. i-FIlens coatings anti-glare coatings that filter out harsh artificial reflected light. Specially formulated tints condition and shift the color spectrum to provide superior contrast, detail and resolution. Frame Design - built for visual endurance, GUNNAR frame systems are engineered for optimal weight, comfort and durability.