Polarised vs Tinted Sunwear
Most people are aware that the sun can be harmful to your eyes so will choose to wear sunglasses for protection as well as comfort in the summer months. But did you know that in the winter months glare can be just as troublesome as the bright summer sun?
If a patient tells their Optician that they are often in positions where glare is a big visual concern, a recommendation for polarised sunglasses in place of tinted sunglasses may be made. However, most people may not understand the difference between the two types of lenses.
We would like to talk about the differences and explain how, in the winter months especially when the sun is not particularly warm but is low, polarised sunglasses can still be more beneficial than tinted spectacles.
Apart from being made in a different way the biggest difference for the wearer is the visual comfort that a polarised lens can provide.
Without bamboozling you with all the technical terms we first need to have an idea about how light enters our eyes to be able to explain polarised lenses. Here's the scientific part made easy......
Light from the sun or an artificial source travels in a straight line, bounces off objects and into our eyes. These straight lines of light are basically made up of waves that travel up and down (vertical plane) and side to side (horizontal plane). When this light bounces off reflective surfaces such as a lake, snow, wet roads or wet car bonnets, it can cause what is known as glare.
A polarised lens is designed with a series of laminated films over the front surface that will cut out the horizontally moving light so that light enters the eye more directly. When this happens the wearer experiences glare free and more comfortable vision.
A tinted lens is produced differently. It is dipped into a colour coating and a UV filter is applied. This will protect your eyes from the most harmful Ultra Violet rays but will not eliminate the horizontal rays from reflected light. A tinted lens will dull bright lights but glare can still effect the wearer and leave them feeling as if their vision is not clear.
There is a way to check if the glasses you are about to purchase are in fact polarised. Due to the way the filters are designed in polarised sunglasses, if one pair of polarised lenses are placed over a second pair at a 90 degree angle, you should not be able to see anything through the overlapping lenses. If you can still see through the lenses they are not polarised lenses.
As with purchasing any glasses, the options available to the individual patient vary. Polarised lenses come in a range of colours offering patients more choice, so it is always worth talking to your optician about what may work best for you. We have plenty of advice and examples within practice so why not call in and see for yourself.