'''Ultraviolet''' (UV) [[light]] is [[electromagnetic]] [[radiation]] with a [[wavelength]] shorter than that of visible light, but longer than [https://en.wikipedia.org/wiki/X-ray X-rays], that is, in the range between 400 nm and 10 nm, corresponding to photon energies from 3 eV to 124 eV. It is so-named because the spectrum consists of electromagnetic waves with [[frequencies]] higher than those that humans identify as the color [[violet]]. These frequencies are invisible to most humans except those with [https://en.wikipedia.org/wiki/Aphakia aphakia]. Near-UV is visible to a number of insects and birds. | '''Ultraviolet''' (UV) [[light]] is [[electromagnetic]] [[radiation]] with a [[wavelength]] shorter than that of visible light, but longer than [https://en.wikipedia.org/wiki/X-ray X-rays], that is, in the range between 400 nm and 10 nm, corresponding to photon energies from 3 eV to 124 eV. It is so-named because the spectrum consists of electromagnetic waves with [[frequencies]] higher than those that humans identify as the color [[violet]]. These frequencies are invisible to most humans except those with [https://en.wikipedia.org/wiki/Aphakia aphakia]. Near-UV is visible to a number of insects and birds. |