4 Base Curvature - The base curvature corresponds to the curve of the lens. The higher the number, the higher the curve. 4 base styles have a “flatter” look. 6-9 base curves hug closer to the face.
These measurements include the width of the lens, the width of the bridge and the length of the arms measured in millimeters. For example, a 58-18-144 frame breaks down like this:
1) Lens Width - 58mm
2) Bridge Width - 18mm
3) Arm Length - 144mm
Polarized Multi-Layer Lenses - The polarized lenses set in the frame offer clarity and are extremely durable. Polarized lens technology also protects you from the dangers of UV rays and glare.
CR-39 Lenses - CR-39 lens technology provides you with a clearer view of the world around you, though it's not as impact resistant as polycarbonate it provides you with a better, clearer, and more accurate view.