Coyote Eyewear BP-4 Polarized Reader Sunglasses BP-4 measures 64mm; large fit This polarized lens delivers class 1 optics with the added benefit of bifocal / reading power Bifocal segment fully integrated to the back side of the lens making it unnoticeable to onlookers Extremely Impact resistant lens - ANSI rated Z89.0 Gray tint offers natural color transmission and a cooling view