The truth about polarization

The process of transforming unpolarized light into polarized light is known as polarization. Learn about polarization in the transportation sector

June 6th, 2017 | Customer Focus

Photo Credit:©


Look at this picture: can you tell what the middle gauge indicates?  No, of course not. Why? Because you obviously can’t see a thing, and neither do we! You probably already have encountered this problem when driving: the reflection of the sunlight and its glare on dashboards and instrument panels prevents the driver from reading the information correctly. More than just annoying, this effect can even be dangerous for the drivers in some circumstances. But why is it so? And what can we do to prevent this? 



Actually, the glare of the sun is highly polarized. Most of the time, sunlight scatters in all directions except when it's reflected from flat surfaces: it then tends to become polarized. This means it travels in a uniform, horizontal direction. This polarized light creates an unusual intensity of reflected light that causes glare and reduces driver’s visibility. Depending on the height of the sun, its glare can be almost completely horizontally polarized, generating glare-causing reflections from flat surfaces. The information below the flat glass panel here in the picture is thus totally washed out. 


A good pair of polarized glasses is the solution to this problem. The polarized sunglasses have special filters -polarized filters- with the transmission axis oriented vertically to block the light reflected horizontally by the flat glass panel. The line joining the temples of the filter always remains horizontal and the sunglasses continue to block the glare if the driver moves his head up or down. Of course, if he leans his head to one side, the filters start to point in the wrong direction and the vision is blurred. But you’re not supposed to do that while driving. Thanks to their capacities, polarized glasses are thus very popular with truck drivers and taxi drivers.


So now, put your polarized sunglasses on and magic… the glare disappears! 

With polarized sunglasses, the glass panel on the gauge appears more transparent and the information below is revealed! 



A side by side before/after picture for a comparison with or without polarized filter: 


With SPEOS – the optical simulation software based on the physics laws of light and human vision – automotive manufacturers and their Tier-1 suppliers can easily simulate annoying glare effects. Experimenting their future product dynamically, in real time, in a VR solution, they can detect annoying effects early on their virtual prototypes. Thus, they can improve the design of the car early in the process and minimize these effects. While saving time during design and validation process, virtual prototyping will guarantee the release of a secure product that improves users' experience.