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What are polarised lenses?

You have surely heard the term "polarised lenses" before. It's a term thrown around quite a lot, kind of like "electrolytes". We know it's a good thing and any sunglasses that come with polarised lenses must be good. But what are polarised lenses? What benefits do they provide us and how do they work? 

Well that is our topic of conversation today. So without further ado, let's dive in.

What is polarised light?

In order to understand how polarised lenses work, you first need to understand what polarised light is. As we know light is made up of particles and those particles move in waves. What you probably don't know is that those waves vibrate in all different direction. This is called unpolarised light.

There are times when light waves can vibrate in the same direction and this generally happens when light bounces off a flat surface, such as a window or the calm water surface in your swimming pool. When this happens, all the light waves polarise, that is to say they all realign to vibrate along the same pole at the same time. This is called polarised light, and this type of light is the cause of glare.

How do polarised sunglasses work?

The name itself – "polarised sunglasses" may be misleading. Polarised lenses are not designed to polarise light, but rather they are designed to filter out any polarised light before it reaches your eyes. Basically they do this by blocking any light waves that are oscillating vertically, while allowing all other forms of light to continue on through the lens.

While the term polarised lenses has only been thrown around a lot the last decade or so, they were in fact invented long before then in 1936 by Edwin Land, the man who started the Polaroid Company. He found that if you suspend a compound called "herapathite" in a clear polymer, they act like bouncers for your eyes by blocking potentially strenuous polarised light and letting in the rest.

A lot of companies wrongly advertise clearer vision in polarised sunglasses, but the truth is that it does not make your vision more clear as much as it prevents light from disturbing your vision. This means you can see more clearly than you would have if you were looking at something causing a glare, but it doesn't in fact improve your ability to see.

Should you wear polarised lenses?

In essence the purpose of polarised sunglasses is to reduce eye strain caused by glare. So if you are wondering if you should be wearing polarised lenses in your sunglasses, then first take a look at what you will be doing. Often high quality brands of sunglasses will offer different types of sunglasses for different types of activities, such as Oakley's Prizm lenses. Polarised lenses reduce the glare caused by sunlight hitting flat surfaces, so examples of activities where polarised sunglasses would benefit you are driving, any water sports and skiing.

If you have any more question about polarised lenses and how they will benefit you, why not give our qualified optometrists a call and chat with them in person? You can reach them by dialling 0861(MYEYES) 693 937 and choosing the store closest to you.