Polarized Sunglasses Explained
Polarized sunglasses have been popular with boaters and fishermen, who need to reduce reflected glare from water, for many years. Lovers of the outdoors have discovered the benefits of polarized lenses, and as a result, interest in these types of sunglasses has soared.
Polarized light is a concentration of light waves moving in the same direction and along the same plane. Light is like a wave that vibrates in many directions—it can vibrate from side to side or up and down. Light reflected from surfaces such as a flat road or smooth water generally is horizontally polarized. This means that, instead of light being scattered in all directions in more usual ways, reflected light generally travels in a more horizontally oriented direction. This creates an annoying and sometimes dangerous intensity of light that we experience as glare. This glare can cause eye fatigue, headaches, or temporary blindness, which can lead to collisions or injuries. Polarized lenses contain a special filter that blocks this type of intense reflected light, reducing glare.
Polarized sunglasses neutralize horizontal reflection of light by screening it through vertically oriented polarizing filters embedded in or applied onto the sunglass lens. Only the part of the light wave that is aligned with the microscopic openings (vertical) in the filter can pass through, while the reflected light that is horizontally oriented is blocked. The result is that the glare is significantly reduced. These vertically oriented polarizers effectively behave like high-tech Venetian blinds, filtering out the reflected light.