Foggy safety glasses are not only annoying, they can be dangerous as well. When your lenses fog up in the middle of a project, you might be tempted to take them off or adjust them in a way that ends up keeping them from doing their job. To keep your glasses from fogging up, you can try a number of different options that range from spitting on the lenses to purchasing anti-fogging solution to buying anti-fogging safety glasses.
Purchase specially made anti-fog safety glasses. DeWalt and many other companies make safety glasses that are specifically created so that they don't fog up. Most are fairly inexpensive. Check at your local hardware store or online to purchase a pair.
Wash the inside of the safety glasses with dishwashing detergent or shampoo. The brand does not make any difference. Buff the detergent or shampoo off of the lenses with a soft cloth.
Apply uncolored beeswax to the inside of the lenses. Buff well until the lenses are clear. This application will last about two weeks. Repeat the process as needed.
Spit on the inside of the lenses. Some people say that this is the easiest method to keep safety glasses from fogging up, while others prefer more hygienic solutions.
Apply a defogging solution such as Defog It or Rainex. Dive shops also sell solutions you can use to prevent fogging.
Clean your safety glasses with regular -- non-gel -- toothpaste. Remove the toothpaste carefully with a soft cloth; you don't want to get it in your eyes when you wear the glasses.