Overexposure to the suns ultraviolet (UV) rays has been linked to cataracts and other eye health problems. UV also causes pre-mature wrinkling and aging of the delicate skin around the eyes. People have learned to protect their skin with sunscreen lotion. Protecting your eyes from exposure to the sun is just as important.

Many lenses come with built in UV protection. UV coatings can also be applied to provide protection.
Polarized lenses, polycarbonate, and Transition lenses, as well as non-glare coating provide UV protection.
When light hits a reflective surface, such as water, snow, even cars and buildings, the light can become polarized, resulting in glare that can interfere with your vision. Only polarized lenses can remove this glare, working much as a venetian blind to block out horizontal polarized light waves.

We’ve all experienced glare in our daily routine, perhaps spending the day at the beach or fishing with the sun illuminating the surface of the water, or driving in a car with the sun reflecting off the dashboard, roadway or hood. This glare is bothersome and uncomfortable on the eyes, but when the angle of reflection is just right, the glare can become blinding and often extremely dangerous, as in the case of driving a vehicle.

Rollover to see a comparision of the Non-polarized and Polarized Lenses
Regular tinted sunglass lenses only reduce ambient light that reaches the eye, or, light transmittance. By their very nature, they cannot block glare. Only polarized lenses can block out this dangerous, blinding glare.