You’re about a minute or two into a climb and you’re just starting to get uncomfortable. You unzip your jersey a bit to get a bit more air. Your glasses then start to fog up allowing you to see basically nothing. You’re focused on the effort and now you’re irritated with your glasses. You try wiping them with a finger and now you can’t see anything. With your glasses fogging up it can be irritating as well as dangerous. Keeping them from fogging up in the first place can save you a lot of hassle.
Reasons For Glasses Fogging Up
Glasses fog up because they are at a lower temperature than the heat emitted by your face. When the air from your face hits your glasses, the lower temperature causes the air to condensate, or in simpler terms, the moisture in the air turns to a liquid on your glasses. This is physics and the amount at which it occurs is determined by temperature differences and how much moisture is in the air which is also increased because of the moisture coming off your face as well.
The colder the temperature outside, the easier it will be for your glasses to fog up. The large temperature difference can cause your glasses to fog up even if there is a lower amount of moisture in the air.
A high humidity, such as when it’s foggy, causes droplets of water to form at lower temperature differences which is why your glasses almost always fog up in this scenario.
When it’s raining is similar to when it’s humid out. There is a lot of moisture in the air and the rain on the glasses themselves can also cool them down slightly upping the temperature difference.
Glasses Too Close To Your Face
In combination with all of the factors above, having your glasses too close to your face decreases the amount of air flowing through to dissipate the heat thus resulting in a higher likelihood of you glasses fogging up.
How To Stop Your Glasses From Fogging Up
Unfortunately with cycling you are always going to run the risk of fogging up your glasses. It’s simple physics but there are things you can do and use to lower the likelihood that they fog up.
Using Your Breath or Saliva and Wipe
The simplest and easiest way to lower the amount that your glasses fog up is to fog them up with your breath and then wipe them clean with a clean fabric such as your shirt. (Jersey material is often a poor choice but t-shirt material, cotton, works well.) If your glasses tend to fog up a lot you can take this one step further and spit on them, mainly the inside of the lenses. Wipe them with your finger to evenly disperse the saliva and then wipe them clean.
Another solution to glasses fogging up is to use anti-fog wipes or spray. These use compounds that prevent the forming of water droplets on a surface. They are easy to use as long as you have them readily available. Chances are you won’t have them in your jersey pocket should you need them mid-ride.
A home remedy to glasses fogging up is to use shaving cream. Simply put a light dab on your finger and rub the lenses and then wipe clean with a clean fabric.
Positioning Them Further From Your Face
In addition to the above fogging solutions, you should also position the glasses so they sit a bit further away from your face. This will allow air to flow more easily between your lenses and skin to lower the heat difference. Some glasses are better for preventing fogging while some are worse. When looking for a pair of glasses, make sure they fit your face well and aren’t too close. A good option is to get a pair with an adjustable nose piece to position them where you want them.
Taking Them Off
In some conditions keeping your glasses from fogging simply isn’t going to happen. The best solution here is to simply take them off as they start to fog. This will keep them from completely fogging over as well as you wiping them to keep them clear which then leaves marks for you to look through the rest of the day. Then when you’re done with the climb, just put them back on.
Having glasses fogging up can be a real pain but with these solutions you should be riding with much better vision whether prescription glasses or just sunglasses.