Polarized sunglasses are extremely popular because they reduce reflections and protect the eyes from the sun. But how do you know if the glasses you bought really have polarized lenses? We'll explain.
Method #1 - The reflective surface test
Choose any reflective surface. It can be a mirror, a table, or any other surface capable of reflecting light perceptibly. If you don't have light capable of creating a reflection, use a flashlight or other light source to achieve the desired effect.
Place your sunglasses in front of your eyes, 15 to 20 cm away from your face. You should be able to see the surface through one lens at a time. Tilt your sunglasses slightly and look through the lenses. If the sunglasses are polarized as you rotate the lenses, the image will be dark and almost glare-free, although you will probably see some of the light illuminating the surface. If you have doubts about the result, rotate the glasses up and down to confirm the polarization effect.
Method #2 - Use another pair of polarized sunglasses
If you already have a pair of polarized glasses, do a comparison test. Align one of the spectacle lenses you want to test behind one of the spectacle lenses that you already know are polarized. With a distance of approximately 5 cm between the glasses. Don't let the lenses come in contact with you because they can cause unnecessary damage.
Then point the glasses to a visible light source, preferably natural, and tilt the glasses you are testing so that they are in a perpendicular line to the glasses you already know. If the glasses are polarized, your lenses will appear darker. If the lenses do not change their colour, then they have no polarizing filter.
Method #3 - Using the computer screen
Put the sunglasses in front of the computer. Tilt the glasses approximately 60º to the right and left. If the lenses have a polarizer filter, the computer screen will turn black when viewed through the lens.
That's it! Here you have 3 simple tests that allow you to quickly check whether the sunglasses have a polarizer filter or not.