Polycarbonate is though and resistant material that is used manufacture bulletproof widows, for airplane windows, the helmet visors of astronauts as well as space shuttle windshield.                                                                           

Polycarbonate lenses are made of polycarbonate which is a though, lightweight and almost unbreakable plastic. Although thinner and lighter than the conventional plastic lenses, they combine the best features of all those lenses and offer complete protection from sun’s harmful UV rays, protect the eyes from cataract, partial to total blindness and other problems, and provide about 10 times more resistance to impacts than normal glass or plastic lenses.