As I highlighted in the current issue of AMC Outdoors, there really is a product called Cat Crap. It's been my go-to anti-fogging treatment for goggles for many years. That's not to say there aren't other options, many of which perform adequately.
Photo: Joe Shlabotnik/Flickr
Regardless of which anti-fogging product you choose, however, it's important to understand one thing: There is no truly fog-proof treatment for your goggles or glasses in existence, especially if you're out in very cold conditions. Based on my experience, different products all help reduce fogging, but none of them completely eliminates it. Which is why it's so important to first hew to the following guidelines.
Anti-fogging basics 1. Don't funnel your moist breath into your goggles or glasses.
A fully zipped jacket collar, neck gaiter pulled over your lower face, or poorly venting face mask can all direct your warm, moisture-laden breath upwards and onto your eyewear lenses. Sort out your clothing system before you hit the cold-weather trails to avoid this.
2. Minimize sweating.
While it's impossible to completely eliminate sweating, you should avoid episodes of profuse perspiration, which create ample amounts of moisture around your head and face that make fogged lenses much more likely.
3. Go big on the goggles.
Larger goggles generally provide better airflow, which helps reduce the likelihood of fogged lenses. "Over-the-glasses" (OTG) goggles are larger styles designed to fit over regular glasses and a good option for minimizing fogging.
Though it's hard to beat Cat Crap, a range of other options are out there. Some of the better ones include Fogtech DX, available as either a liquid treatment ($11.98 on Amazon) or disposable wipes ($1 to $2 per wipe, depending how many you buy); TYR Anti-Fog Spray, an inexpensive but reasonably effective liquid treatment ($3.99); and Oakley's Nanoclear Hydrophobic Lens Cleaner Kit ($20), a well-reviewed liquid treatment that provides nanoclear vision, whatever that means.
As a general rule, definitely choose liquid treatments over wipes—though they are slightly messier and less convenient to apply, they last much, much longer.
Alternatively you can invest in some newfangled goggle technology. Some higher-end models feature small, battery-operated fans to help eliminate moisture, while others feature heated lenses that keep moisture at bay. Expect to pay $150 or more for either option.