Airborne flotsam and jetsam isn't the only stuff that can do a number on our eyes. Glare from reflecting surfaces can cause eyestrain and prevent us from focusing on the job at hand or enjoying outdoor activities. Besides being super durable and scratch-resistant, polycarbonate safety glasses lenses provide built-in protection against harmful ultra-violet rays as well as greater visual acuity. These so-called polarized lenses work similar to a Venetian blind in that they let in light at certain angles only. Without the sun's glare, objects become more distinct and are seen in their true colors. If you work or play outdoors, polarized safety glasses are just what the ophthalmologist ordered.