||Human Homo sapiens
||John Moran eye center, Uni. of Utah, Webvision, the organization of the retina and visual system, Helga Kolb, Eduardo Fernandez and Ralph Nelson, link
||Wandell, B.A. (1995) Foundations of Vision. Sinauer Associates, Inc. Sunderland, Massachussets.
||See Rushton 1965 PMID 14296430 p.20 bottom sentence:"The pupil diameter lies between 2 and 8 mm, which can only provide a change in area of 16 times to deal with the 10^10 light span."