Are made from a special polarizing film that is applied in the factory on the front surface of the lens, this film allows light rays to be filtered, thus improving the vision in strong light conditions.
The rear surface of a special thick semi finished polarized lens can be ground and polished to produce a prescription lens, they have to be made bespoke so as to keep the polar axis in line.
They will protect you from UV rays, glare and intense light.
When combined with a antireflection coating they are ideal for fishing and driving.