Description : Hi-Index Lenses
Single Vision Lenses:- These are the lenses which are used to correct the refractive error for only one distance either for distant or near.
Columbia Resin - 39 ( CR-39 )
Polarised Lenses ( CR-39 ) 1.56,1.57,1.61,1.67,1.74
Glasses Index - 1.7,1.8,1.9
Bifocal Lenses:- These are the lenses which are used to correct for two different distances in just one lens.
Kryptok ( Moon ) bifocal
Flat Top ( D ) bifocal