Why do goggles fog? How to prevent foggy goggles
Every swimmer has experienced foggy goggles. In open water, you can’t see where you’re going. In the pool, there’s nothing more annoying than having to stop every few lengths to clear them out. But why do goggles fog up? Understanding the science behind it and the science behind the solution will help you prevent foggy goggles in the future. Plus, we’ll go through three tips to ensure you’re swimming experience stays fog-free.
Why Do Goggles Fog Up?
The science behind why goggles fog is surprisingly simple. It all comes down to the temperature difference on either side of the goggle lens. When the air inside your goggles is warmer than your goggle lenses, the warm air molecules hit the cooler lens and condense into water molecules. When enough condensation occurs, you get fog. It’s the same reason why we can write our names on glass shower doors, why people who wear glasses always fog up when they open an oven, or why the car windows get misty. When you’re swimming, your body heat can easily create a big enough temperature imbalance and, as we all know, foggy goggles just suck the fun out of swimming.
How to Stop Foggy Goggles
The solution to prevent foggy goggles is—surprise, surprise— anti-fog. Since it would be ridiculous to try and regulate temperature as a lasting solution to foggy swimming goggles, science, once again, provides us a solution.
Anti-fog is a chemical surfactant that works to prevent the condensation process, so water molecules don’t form droplets, or fog. As chemistry professor Joe Schwarcz of McGill University explains, “This can be achieved by lowering the water's surface tension; the force with which water molecules are attracted to each other. The reason water forms beads in the first place is because the attraction of water molecules for each other is greater than for the surface. The idea then is to introduce some substance that gets in between the water molecules and prevents them from sticking to each other. Instead of forming droplets, the water will spread into a thin film which does not obstruct vision.”
Anti-fog for goggles is specifically formulated but there are many “do-it-yourself” versions ranging from shampoo and toothpaste to saliva (yep, spit!) and even fire. All these methods aim to work in the exact same way that anti-fog disrupts the formation of water droplets. While some of these methods are successful and some of them just aren’t, all of them at best are short-lived and none of them work as well as specific anti-fog. All these methods will also damage or destroy any anti-fog coating already in your goggles. Bottom line: Anti-fog is the only real solution.
Anti-Fog for Swimming Goggles
Goggles often have anti-fog coatings nowadays, but it wasn’t and still isn’t always the case. Turns out swimmers aren’t the only ones who have problems with fog getting in the way of sight. In June 1966, astronaut Eugene Cernan had to abandon an experiment during the Gemini 9 mission because the visor of his space helmet was so foggy he had to feel his way back inside the cockpit because he couldn’t see at all. NASA got to work and developed the first anti-fog technology. Since then, technology has continued to progress, and astronauts aren’t the only ones who reap the benefits of anti-fog. Today, anti-fog is commonly used for consumer goods including ski and diving masks, as well as swimming goggles, but it’s also used for industrial and commercial purposes, and even in the military.
All THEMAGIC5 goggles have an anti-fog coating but not all goggles on the market have that feature. When you’re buying goggles, always check to see if they have an anti-fog coating—it should be clearly indicated in the description or on the box. If they don’t, we say skip them and look for different pair. You’ll be glad you did the next time you swim.
If your current goggles didn't come with an anti-fog coating, or they seem to be running out, check out TheMagic5 anti-fog spray!
3 Tips to Make Anti-Fog Last
As advanced as anti-fog technology is these days, it does require care and it does eventually wear out over time. However, there are three steps you can take to prolong the effectiveness of your anti-fog coating.
Rinse with Clean Water:
Shop THEMAGIC5 goggles
These goggles never leak, but they do fog up, and I have never touched inside of lens. What do you recommend?
The fit has been great, not so the anti-fog…I did wipe my previously unused goggles with my t-shirt just before a race yesterday, and it scratched the surface so badly I couldn’t see through that lens. Perhaps the advice about no touching needs to be stronger & more prominent on packaging etc
Now that my son’s anti-fog has been corrupted by sunscreen, what’s the recommended fix?
I’ve written to you before but I feel compelled to write again. I can’t thank you enough for developing this technology and these goggles. You literally saved my swimming life. I’m not sure what happened, but as I aged (I’m 61), conventional goggles stopped working for me. What ever brand I bought would fit on one eye but not the other. If the right didn’t leak, the left did, and visa-versa. As a life long swimmer I grew very discouraged and spent a fortune buying countless brands hoping to find one that worked. Then I found Magic and voila I am back to really enjoying swimming again with absolutely no leaks as well as great visibility. THANK YOU!