In the early 1900s, the use of sunglasses started to become more widespread
, especially among stars of silent movies. It is commonly believed that this was to avoid recognition by fans, but the real reason was they often had perennially red eyes from the powerfularc lamps that were needed due to the extremely slow speed film stocks used.The stereotype persisted long after improvements in film quality and the introduction ofultraviolet filters had eliminated this problem. Inexpensive mass-produced sunglasses were introduced to America bySam Foster in 1929.