What Do Polarized Sunglasses Do?

Although we don’t have an optical shop in our offices on Michigan Avenue, in past Millennium Park Eye Center blogs, we’ve discussed different options for buying new eyeglasses, everything from high-definition eyeglasses to matching your glasses to the shape of your face.

What about “polarized” sunglasses? Patients often wonder what the benefit of polarization is for lenses, so in this blog in the midst of a Chicago February, let’s get into this.

What are polarized lenses?

When sunglasses are polarized, the lenses are coated with a special chemical that blocks some of the light that passes through them. The polarization acts as a filter for the light being reflected directly into your eyes.

It helps to understand what vision really is. Vision happens when your eyes perceive the light rays that reflect off an object. For most objects that light is scattered in some way before it enters your eye. It’s typically bouncing off multiple angles because most objects have an uneven surface. When you’re looking at a smooth, flat, highly reflective surface, such as a lake, a metal roof, or a snowy slope, the light is much brighter. This isn’t the time of day; it’s because more of the light is directly entering your eye rather than being scattered.

Polarized lenses block some of this light, which gives them their quality for reducing glare when looking out over Lake Michigan, for instance. The polarized filter is vertically oriented, so only some of the light can pass through the openings. Because glare is typically caused by horizontal light, polarized lenses block this light and only allow vertical light. This helps eliminate glare.

The good and bad of polarized lenses

If you spend a lot of time outdoors, as we do in the Midwest, polarized lenses are a good option for your sunglasses. These are the advantages of these lenses:

Clearer vision, especially in bright light

Increased contrast and minimal color distortion

Reduced glare and reflection

Reduced eyestrain

But polarized lenses aren’t for everyone. These are the drawbacks to the polarizing process. Polarized lenses aren’t good for…

Looking at LCD screens (such as on your phone)

Flying

Low-light situations and night driving

People whose sight may be sensitive to how the lenses change lighting

So, if you need to see your phone often when wearing your sunglasses, it’s probably a better bet to have sunglasses without polarization. The same is true in lower light situations.

If you’re looking for a new pair of sunglasses, whether prescription or not, polarized lenses could be a good way to go, especially if you’re out in situations with lots of glare.

Otherwise, for all problems with your eyes, give us a call at Millennium Park Eye Center, (312) 996-2020.