Windsor glasses are a type of eyewear that have a distinct round shape and a keyhole bridge. These glasses are sometimes referred to as round eyeglasses, P3 frames or keyhole glasses. They were made famous by celebrities such as John Lennon and Gandhi and have since become a popular choice among those looking for a retro and classic look. Other synonyms for Windsor glasses include circular glasses, browline glasses, round frame glasses and vintage glasses. Whether you call them by their original name or one of the many synonyms, Windsor glasses continue to remain a popular choice among fashion-forward individuals.