Polarized lens is invented by Edwin H. Land in 1936. Ordinary light travels in the form of waves that can vibrate in all directions. It's made of a synthetic plastic, such as CR39 or polycarbonate, with a polarization filter enclosed within it. It's not only for anti-glare but also for general trendy wear. The polarized sunglasses are created for absorbing the reflective solar glare from flat surfaces, like snow, water. This kind of sunglasses can absorb up to 97% of the glare. It's safety equipment for navigators and drivers and other related activities.
At first, the polarized sunglasses are invented as the defence preparations thirty years ago. However, they are now used as the personal wearing use. Polarized light can be divided into three kinds, namely linear polarization, elliptical polarization and circular polarization. The general so-called polarization refers to linear polarization. Now the polarized sunglasses will always be worn by fishers and drivers to protect their eyes from strong lights and help them see clearly.