Polarised Sunglasses

What makes polarised lenses different?

Polarised lenses are different to standard sunglass lenses; they have a special film either sandwiched between two other layers of the lens or applied to the front of a lens. This special film eliminates glare that reflects off a surface like a road, ski slope or water. Light waves from the sun travel in all directions but when sunlight strikes a surface it becomes concentrated – this polarised light, as it is called, causes 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. Glare 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 – a good reason why fishing enthusiasts wear polarised sunglasses.

Glare causes the mirror-effect on water. As a polarised lens will eliminate this glare you can see what’s under the water. Useful for sea fishing and especially helpful to judge the depth of a stream when fly fishing.

Although polarised lenses provide lots of vision benefits it is important to note that the majority of polarised lenses are made from a material called TAC which is relatively thin and does not provide impact protection. For sports such as shooting where impact protection is important a polycarbonate lens is required.

Are all polarised lenses the same?

The short answer is no. As mentioned above, the vast majority of lower priced polarised sunglasses sold (typically under £50) use a lens material called TAC and the polarised film is on the front of the lens. This means over time it can scratch and eventually lose some of its polarising properties. On higher priced polarised sunglasses (typically above £50) the lens material is likely to be polycarbonate or a similar material called Trivex. Here the polarised film is sandwiched between two layers of polycarbonate meaning the polarised film can never wear out. However if you’re happy to change your Evolution polarised sunglasses (the vast majority costing under £20) after around 2 years of regular use, then they will do a perfectly good job.