Fez Caramel | Cat-eye shape. - Frame Color: Brown - Lens Color: Brown - 1 Year Warranty Technical Information: Hand Polished Width-Nose Gap-Height Measurements of this pair: 142-21-51 mm Hinge: Five-barrel. Lenses Technology: ✓ CR-39 Lenses. CR-39 is made by polymerization of diethyleneglycol bis allylcarbonate (ADC) in presence of diisopropyl peroxydicarbonate (IPP) initiator. "CR-39" is an abbreviation of Columbia Resin 39. CR3-9 has the highest Abbe value of any lens. An Abbe value defines the chromatic aberration of material, and this effect is generally more noticeable in peripheral vision than when looking through the center of a lens. ✓ 100% UV Protection. The lenses we use, have a UV protective coating with maximum filtration against harmful sun rays. ✓ Lenses Category: 3. The bigger the category number of lenses, the better. Category 3 in lenses, is considered better than categories 2 & 1. This is because they provide extra protection from both visible and UV light. These lenses allow less than 20% of visible light to penetrate the lens. This means that they will block out 80%+ of light. Category 3 lenses are considered the best lenses in the optical industry.