Polarised sunglasses are just one way to protect your eyes from the sun’s rays, providing they are a decent pair. You don’t need to spend the earth, although a great deal of the designer sunglasses will protect you and are not always as expensive as you may think.
It’s not just in the summer you need worry about the sun but in the winter as well, you also need to consider what you are doing. For example, if you are skiing or snowboarding you need to make sure your ski goggles protect you adequately as the sun will bounce off the snow. However, if there is a danger of thin ice, polarised sunglasses could cause problems because in some cases, definition will be lost because of the lack of reflection off the landscape. If there is no snow but bright conditions you’ll also get this ‘bounce’ effect from wet surfaces. An example of someone who would benefit from polarised sunglasses are fisherman, as these would make it easier for them to see more clearly into the water without the sun ‘blinding’ their vision. Therefore it is important to remember that safety rather than fashion should be your foremost consideration.
Developed originally by Edwin Land around 1936, lenses are now either coated with a protective substance or have a filter enclosed within them. Polarisation absorbs solar glare from reflective surfaces by up to 99% to counteract the bright glare that the eye cannot protect against by restricting the light waves to a singular direction. For example, Oakley sunglasses have optimised polarisation that exceeds 99% protection with the lens coatings being moulded at the molecular level. (For more information on the technology Oakley uses visit their website.)
As there are many replicas around, to test whether your polarised sunglasses are authentic, rotate it and watch to see if the light passing through the lens changes intensity – it shouldn’t. Don’t go for cheap imitations, it is your sight we are talking about. You can pay over a hundred for the Oakley Tangent (see left) or just £35 for the Bloc Cobra Sunglasses.
Your sunglasses should also protect against 100% of all UV rays ( UVA, UVB and UVC). You should also remember that despite the colour or darkness of the lens, it is the clear outer coating that filters the rays and not the colour.
So what should you look for when buying your new sun glasses? Most people are now aware that they need UV protection but just to explain, UV radiation comes in at least two primary forms, UVA and UVB and both carry their own dangers. UVA can lead to premature skin aging while UVB may cause skin cancer. UVC has lower radiation and is mostly found in artificial sources such as certain types of lamps.
Short-term exposure is not really harmful but repeated and extended exposure is. What you need to look for is a 99 – 100% protection against UV, irrespective of the price of your glasses or the darkness of the lens. Although a bit more expensive, even if it’s a second pair, there are certainly many benefits to having polarised sunglasses as well, so do at least consider this option.