1.56 Hi-Vex Lens Just like Tri-Vex, light-weight, impact resistance, clarity, UV protection Light-weightWith a Gravity of 1.25, compared with ... PC 1.22 and CR-39 1.32, Hi-Vex is an optimal choice ... .Clarity With Abbe Value of 46, Hi-Vex is popular for providing an unsurpassed visual comfort and great transparency.1.56 Hi-Vex Lens