Tips to Remove Fog from Eyeglasses

When you are out in the cold on a chilly night, you may notice a buildup of fog on your lenses. This is a common problem and becomes particularly acute and annoying if you are a paramedic, fireman, rescue personnel, or police officer. Fog forms on the eyeglass surface when water vapor in the air condenses. It happens when the atmospheric air temperature is higher than the temperature of the lens and is especially noticeable when a person moves from a cool room to a warmer one.

Fog is actually a cluster of tiny water droplets bonded to the eyeglass surface. This reduces the light passing through and affects visibility. There are fog-preventing solutions, such as Optifog Activator from Essilor, that keep lenses free of fog by spreading the water droplets evenly. This distributes the fog on the lens surface, making it invisible. These solutions are available for various lens materials, including plastic, polycarbonate, and high-index plastic. The solution needs to be applied once a week.

Polyvinyl alcohol can also be applied as a permanent coating on lenses. This coating is also used on camera lenses, car windshields, and other surfaces. The coating is applied four times to form a strong bond with the adjoining layers and does not alter the optical characteristics of the lens surface.