Cycling Sunglasses or sun glasses are a form of protective eyewear designed primarily to prevent bright sunlight, high-energy visible light from damaging or discomforting the eyes and small bugs and other road debris entering the eyes. They also function as a visual aid, as variously termed spectacles or glasses exist, featuring lenses that are coloured, polarized or darkened. Healthcare professionals recommend eye protection whenever the sun comes out to protect the eyes from ultraviolet radiation (UV) and blue light, which can cause several serious eye problems. Many of the sunglasses featured at fatbirds come with interchangeable lenses for use all year round.