Myth Busting: Toothpaste as anti-fog for your swimming goggles

Updated 26th of June 2021

Fogging swim goggles can be a real frustration. When searching for solutions, too often discussions about using toothpaste on the lenses eventuate. Solutions offered include a quick wipe of the goggles with toothpaste, or at the other extreme, instructions on how to use a Dremel tool with a buffing wheel attachment to polish inside the goggles with toothpaste.

So is there a justification for using toothpaste on your goggles? 99% of the time it’s a definite NO. 1% of the time it’s a poor approach to repairing your goggles.

How did the idea begin?

The idea of using toothpaste began from scuba diving, where divers found that using toothpaste could help with mask fogging. The assumption has then carried across that this approach will work for swimming goggles. But there is a big difference between a diving mask, and swimming goggles. The difference being that a diving mask is made from tempered glass. Tempered glass is very strong, and tempered glass diving masks do not have anti-fog coatings. For a diving mask, the toothpaste acts to clean and potentially remove imperfections or a build-up of grime on the glass surface. When thinking about how this transfers to swimming goggles, we need to understand swim goggle design and anti-fog coatings.

Swim goggle anti-fog coatings

A swimming goggle lens is made from some form of plastic. It’s standard practice these days for swimming goggles to have an anti-fog coating. Well, there are exceptions (especially on cheap goggles, or kids goggles) – but it’s widely accepted that a swim goggle with an anti-fog coating will protect against fogging more than an uncoated lens. This anti-fog coating is applied to the inside of the lens. If you look closely inside the lens of goggles (where the lens and frame are one piece), you can see where the anti-fog coating is applied as there is a slight bump close to the edge of the viewing portion of the lens.

Toothpaste and anti-fog coatings

Toothpaste contains grit, and is abrasive. Put simply, if you apply toothpaste to an anti-fog coating you will ruin the anti-fog coating. The coating will scratch, and the fogging problem will become ten times worse. Avoiding damage to the anti-fog coating is essential if you want to remain fog free.

But for some swimmers, it’s not just a matter of remaining fog free. Some swimmers are never fog free in the first place! In this case, you need to understand common anti-fog issues.

Anti-fog coating issues

There are two main issues that swimmers encounter with anti-fog coatings. They are the quality of the coating, and damaged anti-fog coatings.

Quality of the coating

The reason many people have issues with fogging swim goggles is that some anti-fog coatings are poor quality. Like anything, there are high quality products that will be effective, and poor quality options that cause issues. If you have swim goggles with a poor quality anti-fog coating, you are not going to solve the fogging issue. It’s time for better quality goggles.

Damaged Anti fog coating

The goggle anti-fog coating is fragile. Scratch it and you will get fog that builds outwards from the scratch. The damage sometimes isn’t obvious. It only takes a tiny scratch from your fingernail, and fog can start to build.

Fixing a damaged or poor quality coating

Remember I mentioned that 1% of the time, using toothpaste is a poor approach to repairing your goggles? Well this is the 1%. Sometimes a swimmer will see improvement in fogging if they polish the lens with toothpaste to the extent they completely remove the anti-fog coating. A bad quality anti-fog coating, or scratched lens will fog more quickly than a nicely polished lens. But there’s the catch – you are achieving a sub-par result by removing the anti-fog coating. A good quality anti-fog coating will outperform a goggle without an anti-fog coating. So while you may improve a particular pair of goggles THAT NEED REPAIR, they are not going to perform like new pair of quality goggles with an undamaged anti-fog coating.

Wrap up

Hopefully you’re convinced enough to put that toothpaste tube back in the bathroom where it belongs! Toothpaste won’t help your swim goggle fogging issues. It will in most cases make it a lot worse. If you have a pair of goggles with scratched lenses inside (or poor quality anti-fog coating), sure you can polish off the anti-fog coating for an improvement. But there are better polishing compounds than toothpaste. But do you really want all that work for a sub-par result? The answer for most is it’s time to invest in better quality goggles.