The range of electromagnetic radiation frequencies detected by the eye, or the wavelength range from about 400 to 760 nm. The term is sometimes used loosely to include radiation beyond visible limits
US Department of Labor, Eye and Face Protection eTool: Glossary, Occupational Safety & Health Administration OSHA, Washington, D.C., USA 2010. https://www.osha.gov/SLTC/etools/eyeandface/glossa ry.html, (OSHA/ Eye and Face Prot - Amer) {622}