Most of the "white fog" on glasses lenses will only appear when the temperature difference is large. In winter, the outside temperature is relatively low, and the indoor temperature rises. When it is hot and cold, there will be a layer of "white fog" on the lens of glasses. You can't see clearly with glasses. This requires some tricks to solve.

The economical and practical method is to wipe the glasses with a clean cloth first, then soak the soap in water and wipe the glasses evenly with soapy water. When the soapy water is almost dry, wipe the glasses with a clean cloth again, so that the glasses will look brighter and there will be no more "white fog". This is because soap contains a kind of oil, and "white fog" is actually water vapor. Water and oil have different densities, so there will be no "white fog" after glasses are coated with soapy water.

Glycerol can also be used, and the same is true. Pour glycerin on a clean cloth and rub it on the glasses, so there will be no "white fog" on the glasses. The principle is the same as soapy water. This effect can last for several hours. If you don't have these things around you, the simplest and rudest way is to shout "ha" directly on your glasses with your mouth, and then dry them, and the "white fog" will be gone, but it will be troublesome to repeat it every time.

If you want your glasses to be free from "white fog" for a long time, you can go to the optical shop to buy a kind of anti-fog agent for glasses that specifically removes "white fog". This spray has a good effect. Spraying can last for a day or two, and it can also make the glasses look clearer, cleaner and taste better. I bought one last winter, and the effect is better. One big bottle is enough for a winter. You can save the rest to clean the bathroom mirror.