The American Optometric Association recommends sunglasses whenever a person is in the sun to protect the eyes from ultraviolet radiation (UV) and blue light, which can cause several serious eye problems. Its usage is mandatory immediately after some surgical procedures such as Lasek and recommended for a certain time period in dusty areas, when leaving the house and in front of a TV screen or computer monitor after Lasek. Sunglasses have long been associated with celebrities and film actors primarily from a desire to mask their identity. Since the 1940s sunglasses have been popular as a fashion accessory, especially on the beach.
In the early 1920s, the use of sunglasses started to become more widespread, especially among stars of movies. It is commonly believed that this was to avoid recognition by fans, but an alternative reason sometimes given is that they often had red eyes from the powerful arc 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 of ultraviolet filters had eliminated this problem.