optical lens 1. 100% UV400; Index 1.499 2. various tinted colour 3. high quality, competetive price lens , CR-39 tinted lens, optical lens: 1. Nd: 1.499, UV400, UC or HC or HMC2. Plano, or, SPH6/CYL23. Diameter: 70mm/75mm/80mm4. Base curve: 600B /800B5. Center thickness : 1.9mm / 2.0mm / 2.2mm /2.5mm6. Colour: Full / Double / Progressive any color can be made: Brown, Grey, Green, Pink, Purple