While these three numbers might not say it on their own, they represent one of our high-quality pair of sunglasses with polarized lenses and High Chromatic Definition coating.High chromatic definition High Chromatic Definition (HCD) polarized lenses with an anti-reflective coating to reduce glare while still delivering superior color clarity. Polarized lenses Polarized lenses filter light, eliminate glare, improve visual clarity and definition and shield your eyes from harmful UV rays. Impact resistant Our nylon lenses have higher impact and stress resistance, flexibility, and versatility than polycarbonate, plastic or glass lenses. Dust and water-repelling The oleophobic coating prevents scratches and dust, while the hydrophobic coating repels water. Gently rinse in warm water with mild liquid dish soapy. Dry using a clean, soft, absorbent cloth.