Optical features

Property NXT® CR-39TM PC >1.60 Index
Test EN166 Pass Pass Pass Pass
MIL standard 2,45mm Pass Fail Pass Some Pass
Specific Gravity 1.11 1.32 1.22 1.30-1.40
Refractive Index 1.53 1.50 1.59 >1.60
Abbe Number (2) 45 58 29 32-42
Production Method Casting Casting Injection Molding Casting
Chemical Resistance Good Good Poor Medium
Stress Cracking Not Brittle Sensitive Medium

Next comparison:

  NXT® CR-39TM PC >1.60 Index
Superior Optical Quality (Abbe) (benefit: clear vision) +++ ++ - +
NO Internal Stress (benefit: reduced eye fatigue) ++ ++ - ++
Chemical Resistance (benefit: durability) +++ ++ - +
Stress Cracking Resistance (benefit: durability & safety) ++ - - +
No Rainbow Effect (benefit: cosmetic quality) ++ ++ - ++
High Impact Resistance Test (benefit: protection & safety) ++ - ++ --
100% UV protection (benefit: health & safety) √ √ √ √