More about polarised sunglasses
Polarized sunglasses were first invented by Polaroid in 1935. They differ to standard, non-polarized sunglasses lenses by having a special film either sandwiched between two other layers of the lens or applied to the front of a lens. What this special film does is eliminate glare off a surface like a pavement, road, water or snow. Lightwaves from the sun travel in all directions but when sunlight strikes a surface (and that includes water), it becomes concentrated – this polarised light as it is called causes harsh glare. Non-polarized sunglasses only reduce the amount of light entering the eye; they don’t block glare. Polarised lenses block glare and allow only useful vertical light to enter so you can see much more clearly. Glare makes it difficult and uncomfortable to see and can cause eye strain. It also distorts the true colour of objects and makes them harder to distinguish. With polarised sunglasses you get glare-free vision, clear contrasts, more natural colours and reduced eye fatigue. Because prolonged exposure to glare on the water causes eye strain it can in turn lead to headaches.
Glare also causes a mirror-effect on water. As a polarised lens will eliminate glare on the water, for fishing enthusiasts it means they can see down below the surface. The two most popular polarised lens colours are grey and brown but polarised amber and yellow are also available (see our fishing section).