CR39 Plastic

Meant for simple prescriptions that require sharp optics at a low price point. Not available for rimless, semi-rimless, or wrap (or sport) frames

Polycarbonate

Impact/shatter resistant and 25% thinner than the standard 2739 lenses

1.67 High-Index

Exceptional comfort. 40% thinner and lighter than the standard CR39 lenses. High-Index is recommended for strong prescriptions where total power is _+/- 4.0 or higher