From Maui Jim, the McGregor point mirrored polarized sunglasses feature:

• PolarizedPlus®2 eliminates 99.9% of glare; blocks 100% of UV rays
• patented multi-layer design and lens treatment to maximize color transmission and enhance visible color
• bi-gradient mirror eliminates overhead and reflected glare
• in HCL (High Contrast Lens) for added contrast on overcast or foggy days
• Maui Evolution® lightweight; scratch and impact-resistant
• complements round, oval, oblong or heart/triangle shaped faces; best fits medium sized faces
• anti-corrosive spring hinge
• waterproof and oleophobic coating sheds water and snow and repels grease and smudges
• acetate frame