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.