Probably the most frequently asked question is "Are these fog-proof?" Answer - NO! Nothing is "fog-proof". Anyone who says they have a fog-proof goggle, ESPECIALLY a prescription goggle, is doing two things, dreaming and fibbing.
One prescription ski goggle manufacturer claims "Not an Insert!" about their prescription goggles, like this is some breakthrough technology. Actually what they have is basically an insert that is also the goggle lens. Not only is this extremely ugly, but the lenses are now exposed to the outside elements, allowing them to scratch easier.
Somehow, these are supposed to fog less, which isn't accurate because what always fogs is the prescription lenses, and eliminating the goggle lens is not going to change that. But it's an interesting sales pitch.
Pro-Vue prescription goggles fog less than wearing eyeglasses under goggles because the prescription lenses don't rest right on your face, but they will fog easier than a pair of standard goggles with nothing inside them. I can't guarantee that your Pro-Vue's are going to be fog-proof, because I can take my own Pro-Vue's and in about 3 seconds make them fog and stay fogged all day long. I can also use them all day long and have no problems with fog. Yes, they fog up if you're going really slow or are sitting still, but if you pull the goggle out from your face for a few seconds they will clear. It's all about preparation and knowledge.
If your goggles are fogging, it's because you are allowing warm moist air to get inside them. You just need to figure out how to keep them dry. This is the goal: Keep the goggles dry. Here are some tips for beating fog:
Before you ever go riding, put on your helmet and whatever you plan on wearing on your face under your goggles. Look in the mirror. It is important that the goggles are sealed tight against your face, especially across the bottom. Figure out what it takes to make them seal before you even try using them. Figure out how to make sure your breath cannot go up into the goggle. This is the key to eliminating fog.
• What I personally have found that works best for me is to wear a Proclava under my helmet which keeps my head and neck warm, and a piece of Face Tape under my goggles which keeps me from freezing my nose and also makes a great seal to keep my breath out of the goggles. Both of these products can be seen on the Snow Goggles page.
Use a Smith No-Fog cloth on the prescription lenses each time before you go riding; take ONE light breath into the goggles which will fog the prescription lenses, then buff them with the No-Fog cloth. Do this while you are still inside where it is warm.
Don't put your goggles on while you are standing around or unloading your snowmobile from the trailer. Putting your goggles on should be the last thing you do before you take off, and you should try to keep them warm and dry until you are ready to wear them.
Hold your breath while you put on your goggles, you do not want to get any moisture in them.
If your goggles fog up right away or while you are riding, it's because they are not sealed to your face properly. Some "breath deflectors" are too bulky and will deflect your breath right into the goggles. No good.
If you stop on the trail to talk or look at a map and your goggles start to fog, you need to get air moving through them or take them off. Do not set them on top of your helmet or in front of your face as breathing near them will add moisture and more fog.
If you stop for gas, leave the goggles outside when you go in to pay for the gas unless you plan to stay inside at least 15 minutes.
If you stop for lunch, definitely take the goggles inside to let them get warm and dry.
Be careful to not drop the goggles in the snow, if they get snow in them they will not work again until they are completely dry.
If you are riding in powder, I would tape up some or all of the vent holes on the front of the goggle lens, these holes will let snow dust filter through to the inside.
Some riders like to tape off the bottom venting foam on the goggle frame, this keeps your breath from getting inside the goggle when you breathe. The goggle will still vent through the foam at the top and sides of the frame.