Researchers at the University of Tokyo’s School of Medicine have shown for the first time that caffeine intake can significantly increase the eye’s ability to produce tears, a finding that could improve treatment of dry eye syndrome.

A recent study found that cold temperature causes the oily, outer layer of your tear film to thicken and stiffen, so that it can’t spread well across the eye. This oily substance, called the meibum, is necessary to prevent evaporation of the tears on your eye’s surface.

In fact, the meibum can solidify in cold temperatures and block the meibomian gland ducts, thereby preventing release of meibum into your eye.

Wearing goggles when it’s cold and windy would not only help keep your eyes warm, but would also keep out wind that would evaporate your tears.