Ultraviolet light is emitted by the sun. Ultraviolet radiation is related with hot objects. Examples are stars with surface temperature in range of 50,000 to 1000,000 K and hot gas clouds found between the stars. Overexposure to these ultraviolet waves can cause painful eye irritation, sunburns and skin cancer. These waves can also cause the destruction of plants and the breakdown of the ozone layer.
Ultraviolet exposure can also damage and kill plants.
Some photobiological effects include cell mutation, interference in the division of cells and an increased rate of respiration. Other devices include UV detectors, phototubes, photovoltaic cells, and radiometric devices. The reflection of UV rays off wings help insects identify mates. Birds have the ability to see ultraviolet light as well as the primary colors. Research indicates that this ability plays a role in bird's reproductive habits, as they prefer mates that detect ultraviolet light.