Sunglasses or sun glasses are a visual aid, variously termed spectacles or glasses, which feature lenses that are colored, polarized or darkened to prevent strong light from reaching the eyes. In the early 20th century they were also known as sun cheaters (cheaters being an American slang term for glasses).
Many people find direct sunlight too bright to be comfortable. During outdoor activities, the human eye can receive more light than usual. Health care professionals recommend eye protection whenever outside to protect the eyes from ultraviolet radiation, which can lead to the development of a cataract. Sunglasses have long been associated with celebrities and film actors primarily from a desire to hide or mask their identity. Since the 1940s sunglasses have been popular as a fashion accessory, especially on the beach.