(WUTR/WFXV/WPNY-TV) – One item that’s almost always on the list for a day at the beach is a pair of sunglasses. You might have seen that some glasses are polarized, but what exactly does that mean besides a few extra dollars tagged onto the price tag? Well, for an object to be polarized means that it will block the bright, reflective light and glare from surfaces such as water and roads.
To test if sunglasses are actually polarized, you can use a trick taught in the video here by renowned Physicist and YouTube content creator Dianna Cowern. In her video, she explains that you can hold the sunglasses over your phone while the phone is on and turn them around like you’re turning a knob to open a door. If the glasses are actually polarized, you will see a change in the light, whether it be the color or brightness coming from the phone.
This is because the light from most phone screens is already polarized, meaning the light waves are aligned along a specific direction. The only caveat to this trick is that some screen protectors tend to make the light from your phone more randomly polarized, which means the trick might work differently if you have a screen protector.
Though you can still look at a reflection from glass, water, or even a car window, because some surfaces will still allow you to see the change in reflection if you’re looking at the right angle while turning polarized glasses.