Invisible solar radiation that lies just beyond the violet end of the visible spectrum in the wavelength range from 10 to 400 nanometers (just below the x-ray range) and can harm living tissue. Much of the UV radiation is absorbed by the ozone molecules in the upper atmosphere (stratosphere), but a potentially dangerous amount passes through the ozone hole to cause cataracts, skin cancer (melanoma), suppression of the immune system, leaf damage, and reduced yields in some crops. UV rays are generated also during electric (arc) welding.