Why Do Glasses Fog?

Why Do Glasses Fog?

No matter where you are, and no matter what you’re doing, few things are more frustrating than fogging glasses. To have the precious gift of sight inhibited by this pesky natural phenomenon can be downright infuriating. 

But why do glasses fog? And how can you combat fogging lenses? 

The Science Behind the Smog

Fog is simply condensed water vapor. Put another way, fogging glasses are the result of tiny water droplets covering your lenses. And it is most often caused by condensation, humidity, steam or a combination of these three factors. 

Condensation occurs when warm water vapor contacts a cooler surface. This intersection of water in its gaseous form and a cool surface results in the vapor releasing as liquid on the surface. So, when your warm breath collides with your cold lenses, you’re left with a murky mess.  

Humidity refers to the amount of water vapor in the air. Much like condensation, this airborne water vapor can cause fogging lenses—especially when extreme temperature swings team up with humid conditions. 

Steam can be man-made or natural. It’s simply vaporized water and, when this vapor hits a surface, bam! Fog. However, unlike condensation, temperature differences aren’t required for the buildup of fog. Rather, the airborne vaporized water will attach itself to any surface that gets in its way. Certain tradespeople in the construction field and staff in the energy industry may be exposed to high-steam environments in their daily work. 

Fighting the Fog

Let’s get this straight: fogging is a natural process. And there’s a certain threshold of condensation, humidity and (or) steam that no solution can overcome to completely avoid fogging lenses. In other words, water vapor buildup, and the resulting fog, is inevitable in certain environments. But there are some steps you can take to slow this buildup of water vapor and keep your glasses from fogging.

Washing your glasses with soapy water has been shown to slow the buildup of fog-causing water vapor. Researchers point out that the thin layer of soap left behind after gently rinsing and patting your glasses dry can act as a temporary fog barrier.   

Polish your lenses with a dab of shaving cream. Yep, the stuff sitting in your shower and under your bathroom sink. Like soap, a thin layer of shaving cream can act as a temporary barrier to repel moisture—ultimately acting as an impromptu antifog coating. 

Special antifog sprays can help temporarily prevent fogging lenses. These topical coatings form an invisible layer that can slow the buildup of water vapor on your lenses. However, they will require frequent reapplication, as the chemicals break down throughout the day. 

Try Edge’s Vapor Shield antifog glasses. Instead of a topical coating, like the other solutions mentioned, Vapor Shield antifog technology is infused into the lenses during the manufacturing process. This semi-permanent antifog technology helps inhibit the buildup of water vapor from condensation, ambient humidity and steam. With proper care, Vapor Shield can last for years, not days. And properly caring for our antifog glasses is as easy as it comes. All you need is a bit of water and a soft cloth or one of our microfiber bags—not the harsh chemicals or coatings that other lenses require. 

Seeing it Clearly

Why suffer from fogging glasses when solutions to slow the buildup of water vapor are available? Whether you’re choosing homegrown remedies or modern antifog technologies, keeping your glasses free from fogging can keep you safer at work, more satisfied at play and less frustrated everywhere! 

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