According to today’s data visualization the latest form of sunglasses found were used by the Alaskan Intuit’s. They didn’t use lenses like the current standard sunglasses. Instead they were flattened pieces of walrus ivors with small slits carved out of the eye sections.
In the early 1900s, 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.
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.
Sunglasses offer protection against excessive exposure to light, including its visible and invisible components. They can also improve visual comfort and visual clarity by protecting the eye from glare.
Via: Edel Optics