Polarized sunglasses are very popular because in addition to protecting the eyes from the sun, they reduce the brightness. However, these can cost a lot more money than regular sunglasses, so you’ll want to make sure you get what you’re paying for. You can test the anti-glare technology of sunglasses by looking at a reflective surface, comparing them with another pair of sunglasses, or using your computer’s screen.
Test them on a reflecting surface
1. Find a surface that dazzles you when light reflects on it. You can use a mirror, the surface of a table, or any reflective flat surface. Make sure the reflection is dazzling about 60 to 90 cm (2 to 3 feet) away.
If you need to produce a flash, you can turn on the lights in the room or direct a lamp to the reflecting surface.
2. Hold your sunglasses at least 15 or 20 cm (6 to 8 inches) in front of your eyes. In this way, you should be able to see the surface through one lens at a time. Depending on the size of the lenses, you may need to bring the glasses a little closer to your face.
3. Turn your glasses about 60 degrees up. This is the inclination that the lenses should have, with one of them a little higher than the other. Since sunglasses are polarized in a specific direction, tilting them will make polarization more effective.
Depending on how the brightness affects the surface, you will have to slightly adjust the angle of the glasses to see a noticeable difference.
4. Look through the lenses to check the brightness level. If the sunglasses are polarized, you will notice that the flashes disappear. When you look through one of the lenses, it should look very dark. In addition, you should see the flash less bright, or even it should disappear, but even so it should be noted that the light still shines on the surface.
Move the sunglasses to compare your regular vision with the one provided by the lenses. Do it a few times if you are not sure of the effectiveness of the polarization.
Compare two pairs of glasses
1. Find a pair of sunglasses that you know are polarized. If you already have a pair of polarized sunglasses or if you are in a store where there are several polarized pairs, you can do a comparison test. The test is only effective with another pair of polarized glasses.
2. Take a pair of polarized sunglasses and put the other pair in front of it. Align the lenses with your sight, making sure they are around 15 or 20 cm (6 to 9 inches) apart. Make sure that the questionable pair of glasses is the one near you, and that the polarized pair is farther away.
Make sure that the lenses do not touch each other, as this can cause the coating to scratch.
3. Place the glasses in front of a bright light for more spectacular results. This will help make your test easier, especially if it is the first time you compare sunglasses in this way. The light will make the shading more distinguishable.
You can use natural light that comes in through a window or artificial light from a spotlight or lamp.
4. Rotate the sunglasses you have doubts to 60 degrees. One of the lenses will be diagonal with respect to the other, while the polarized glasses remain in the same position. Only one of the lenses will be aligned with the other pair.
It does not matter in which direction you turn the glasses, but make sure you keep both pairs firm.
5. Look at the superimposed section of the lenses to see if it is darker. If both pairs of glasses are polarized, the superimposed part of the lenses will look darker when you see them directly. If the pair of doubts is not polarized, there will be no difference in color.
You can compare the superimposed part of the lenses with the color of the parts that do not overlap.
Use your computer screen
1. Adjust the brightness of your computer’s screen to the maximum. Most electronic devices have the same anti-glare technology as polarized sunglasses. You will be able to test the polarization by looking at the screen.
Open a white screen, the brightness of the white screen will make the test effect more prominent.
2. Put on your sunglasses. Once you are in front of the computer, simply put on your glasses as you normally would. Make sure you are sitting right in front of the screen.
It may be useful to raise the screen of the computer to the level of your eyes if it is not positioned in that way.
3. Tilt your head 60 degrees to the left or to the right. While facing the screen, lean your head to the left or right of your body. If the glasses are polarized, the screen will appear black because the anti-glare properties will cancel each other out.
If possible, try polarizing your glasses before buying them. Some stores have polarization test tokens that have visible images only when you wear polarized sunglasses.