Different index lenses at Zinff are made of patented materials.
1.56 mid-index lenses are made of KOC 55 developed by KOC(Korea)/Chungho(Korea).
1.60 hi-index lenses are made of KR 60 developed by KOC(Korea)/Chungho(Korea).
1.60 superflex lenses are made of MR-8 developed by Mitsui(Japan).
1.67 hi-index lenses are made of MR-7 developed by Mitsui(Japan).
1.71 hi-index lenses are made of KR 70 developed by KOC(Korea)/Chungho(Korea).
1.74 hi-index lenses are made of MR-7 developed by Mitsui(Japan).
1.50 index lenses are made of CR-39 plastic developed by PPG Industries.