ultraviolet light radiation

Ultraviolet light radiation or UVR are part of the sun's electromagnetic rays that reach the earth's surface. UVR is classified as UVA, UVB or UVC and are not visible to the naked eye. UVC rays do not reach the earth's surface as it is absorbed by the earth's ozone layer. UVB has a wavelength of 320-290 nm and is responsible for sunburning of skin while UVA with a wavelength of 400-320nm is known for penetrating the skin deeper. Both types of UVA and UVB can cause premature skin aging, sun damage and skin cancer.