When looking into a new pair of sunglasses, skiing goggles or any eyewear, you will most likely come across the term polarization.
What exactly is polarization? Light waves travel in various directions. When these waves hit a reflective surface such as metal or water, the waves become more uniformed and horizontal in alignment. This bounces right into your eyes, so the goal of polarization is to block these potentially harmful rays from reaching your eyes.
When you look through a standard pair of non-polarized lenses you will see all light the same way. In other words, everything in you line of sight is basically just darker from the tint of the lenses that you are looking through. This will minimally help with sun by darkening your field of vision.
Polarized lenses will take exactly what you get in your standard pair of sunglasses but with the added benefit of protection from those horizontal rays. So, how exactly do those light waves work? The sun’s job is to produce light waves. And those flow in many different directions. When that light hits a reflective surface, the waves then become horizontal in shape which makes for a very intense beam of light.
This is the glare that you see off water, metal & any other reflective surface. When that light reaches your everyday non-polarized lens you will still see this glare but your vision is just darkened. However, when using a polarized lens the reflective glare (horizontal light waves) is filtered out when hitting the lens and vertical light waves are allowed to pass through. The end result is a drastic reduction is glare—and much better sight of vision for you.
There are a couple different types of polarization. Circular and Linear.
Circular Polarizer is what you typically see in camera filters. You notice while looking through the lens glare will increase or decrease as you spin the filter. These camera filters use a linear aspect on the surface but the light is then bent by what is known as quarter wave. Since polarized film blocks certain angles of light, a cameras mirrors can cause a problem if you are using standard linear lenses. You can replicate this issue by crossing two pairs of sunglasses at a 90 degree angle. It will be a perfect black.
The idea behind using circular is to avoid this cross polarization effect and you can remove glare from your images but still have the proper lighting for lifelike images.