TAC Polarised Lenses Is Composed of 7 Layers of Materials: Sunglasses lens standard,UV400 ultraviolet standard,comprehensive eye protection. Polarised layer:It is the core of the lens.It provides more than 99% polarised effect and absorbs glare effectively. Anti-impact layer:Improve toughness,impact resistance,prevent lens scratch and lengthen the use of lenses. Ultraviolet absorption layer:It can absorb more than 99% ultraviolet radiation.