Tired of your glasses fogging up on cold days, or of having to spit in your dive mask before putting it on? Those hassles may become a thing of the past, as researchers from Quebec City's Université Laval have developed what they claim is the world's first permanent anti-fog coating. Just one application is said to work indefinitely on eyeglasses, windshields, camera lenses, or any other transparent glass or plastic surface.

The actual anti-fog coating itself is composed of polyvinyl alcohol, which is a hydrophilic compound that causes the individual droplets of condensation to disperse. Before it can go on to a surface, however, a base of four successive layers of silicon molecules are first applied via an atmospheric plasma process. These layers bond to one another, but also allow the alcohol to bond to them, ensuring the durability and hardness of the combined coating.

While there are already various anti-fogging substances on the market, some of which even do claim to be permanent, the Laval researchers state that these won't stand up to repeated washings, and need to be periodically reapplied.

The university is currently in negotiations with a major eyewear manufacturer, which is reportedly interested in licensing the technology.

Prof. Gaétan Laroche of Laval's Faculty of Sciences and Engineering led the research, which has been published in the journal Applied Materials and Interfaces.