Sources differ on the range of wavelengths visible to humans. Many articles and books use the range 400 - 700 nm, but do not cite a source for this information. Other sources such as CIE International Lighting Vocabulary (ILV) term number 17–1402 use the range 380 nm to 780 - 830 nm, and there are even sensitivity effects beyond this range under certain conditions (see for example D. H. Sliney "What is light? The Visible Spectrum and Beyond,” Eye, vol. 30, pp. 222-229, 2016). So what standard or other respected source gave us the range 400 - 700 nm?