The striking rectangular design frame of these sunglasses complements a range of facial shapes.Hawaii designated black coral as its official state gem in 1987. Related to sea anemones and stony corals, black coral colonies on Hawaii's deep reef slopes host unique communities of marine life and have been harvested for centuries to be used for jewelry. Early Hawaiians even ground it into a medicinal powder to ward off "evil and injury." Although not made from black coral, Maui Jim's Black Coral Polarized Sunglasses will ward off damaging UV rays. Their PolarizedPlus2 lens technology goes beyond shielding your eyes from glare and harmful UV rays to reveal and enhance the beautiful colors in the world around you. With SuperThin Glass lenses you get Maui Jim's crispest optics and the best scratch and solvent resistance. Lightweight Monel metal frames with acetate temples are durable and resist corrosion. Adjustable, nonslip Rabalon nose pads are included for comfort, stability and to help keep them on your face. Although, if you want to be extra sure they don't end up falling off at an inopportune moment (like when you're leaning over the side of the whale-watching boat to get a closer look at a passing humpback), a neoprene retainer or leash (sold separately) is inexpensive insurance.Lens TintNeutral Gray – this tint has the highest light reduction for rich color and contrast. Best for bright, direct sunlight.SuperThin Glass LensesAbsolute crispest optics available20% thinner and lighter than standard glass lensesPolarizedPlus2 technology eliminates 99.9% of glareSuperior precision with absolute claritySharp contrast with great depth perceptionBi-Gradient mirror at the top and bottom of the lens squints for you so your eyes can relaxAnti-reflective surface blocks bounce-back glare from behind and eliminates eye fatigueEnhance natural light instead of dimming it for exceptional color and clarityBest scratch and solvent resistanceWaterproof and oleophobic to shed water and repel greaseBlock 100% of all harmful UV rays95% reduction in high-energy blue light (HEV)Enhance red, green and blue light wavesMonel Metal FramesNickel-copper alloy with high tensile strength and corrosion