A sudden change in temperature can cause glasses to fog up and is one of the most annoying aspects of wearing glasses in the winter. Applying an anti-fog wipe or spray can help; however, never apply household products like toothpaste or shaving cream to lenses. These internet “fixes” could actually scratch and damage lenses.
There are two dangers to using household items on lenses. First, certain products are abrasive and can cause scratches. Second, certain chemicals can actually strip any type of coating you’ve applied to lenses, rendering them useless.
There are a number of anti-fog sprays and wipes on the market that are safe to use on lenses. Once applied, they create a water-repellent surface, which helps keep foggy glasses to a minimum. While helpful, these sprays and wipes are not a permanent solution, they will usually have to be used multiple times a day.
Another tip to help prevent foggy glasses is to ensure that frames properly fit. Glasses should never rest on your cheeks—if they do—it can contribute to foggy lenses by restricting air circulation. You always want to make sure that glasses sit above your cheeks, even when smiling.