Pal & Pal 2001, стр. 387 Pal, G. K.; Pal, Pravati (2001). „chapter 52”. Textbook of Practical Physiology (1st изд.). Chennai: Orient Blackswan. стр. 387. ISBN978-81-250-2021-9. Приступљено 11. 10. 2013. „The human eye has the ability to respond to all the wavelengths of light from 400-700 nm. This is called the visible part of the spectrum.”
Buser & Imbert 1992, стр. 50 Buser, Pierre A.; Imbert, Michel (1992). Vision. MIT Press. стр. 50. ISBN978-0-262-02336-8. Приступљено 11. 10. 2013. „Light is a special class of radiant energy embracing wavelengths between 400 and 700 nm (or mμ), or 4000 to 7000 Å.”