Group of quantities characterizing visible light in terms of the appearance to the human eye. The symbols of luminous quantities may be distinguished by adding a subscript v. The units for luminous quantities are derived from the SI base unit candela.
See also: radiant quantities, photon quantities
Source:
Green Book, 2nd ed., p. 30 (https://goldbook.iupac.org/files/pdf/green_book_2ed.pdf)