Visible light is a very small portion of the electromagnetic spectrum, EMS. The EMS categories, from long to short wavelengths, are Radio Waves, Microwaves, InfraRed, Visible Light, UltraViolet, X-Rays, and Gamma Rays. Each of these categories can be split into finer categories. Visible light can be broken down by color. A typical human eye responds to wavelengths from about 740 to 380 nanometers, nm. Some animals see a wider range of wavelengths than humans. A rainbow or light put through a prism splits light by its wavelength.