The core of a polarizing lens is a polarizing film. A polarizing film has a Dichroic transparent film. It allows light that is parallel to the direction of the transmission axis to pass, and light that is perpendicular to this direction is absorbed. This phenomenon is called light polarization. .
The light passing through is the same vibration direction and is called polarized light. The reflected light is absorbed because the light becomes perpendicular to the transmission axis of the polarizing film after being reflected. Polarized lenses use this principle to effectively eliminate strong reflected light and scattered light, so that the light becomes softer, so that the scenery that people see is naturally clear.
For a more detailed introductionof polarizing light, please refer to this article: Polarization of Light
Then you bought a pair of polarized sunglasses, how to judge whether there is a real polarized function? Here is how to identify the polarized lens in the simplest and fastest way.
Polarized Test Card
Many eyewear shops have polarized test cards. This test piece is specially made to use the principle of polarized light so that the polarizer can see the parallel light emitted by the picture inside, so that you can see the picture hidden inside.
Tested with two pairs of polarized sunglasses
If there are two pairs of polarized sunglasses and one pair of sunglasses in each hand, firstly overlaps the two pairs of sunglasses horizontally and horizontally and place them in front of the eyes. At this time, you can see the opposite through the “overlapping lenses” with your eyes.
Then rotate one of the pair of sunglasses 90 degrees (that is, one horizontal and one vertical overlap). During the rotation, you can see that the eyes are obviously darkened. If this effect occurs, both pairs of sunglasses are polarized lenses.
Test it on a computer screen
A normal computer screens have a layer of polarizing film, which is mainly used to prevent light damage to the environment, such as fluorescent lamps or other light sources affecting the quality of the screen.
So find a computer screen and point the sunglasses horizontally towards the screen. At this time, the lenses have not changed. Then when you rotate the sunglasses to 90 degrees, you can see that the color of the lenses becomes darker, and then turn back to normal. If there is no change no matter how it is rotated, it is not a polarized lens.
