What are the advantages and disadvantages of polycarbonate spectacle lenses?
Polycarbonate lenses are made by injection moulding.
These lenses have good impact resistance, making them ideal for children, sports and industrial work. They also have good UV protection and a higher refractive index than CR39.
Disadvantages include the fact that their abrasion resistance is poor - adding an anti-scratch coating can help but reduces the impact resistance slightly. These types of lenses cannot be tinted easily, either.