Editing Gustav Fechner (section)

=== Fechner's paradox<!--'Fechner's paradox' redirects here--> ===

In 1861, Fechner reported that if he looked at a light with a darkened piece of glass over one eye then closed that eye, the light appeared to become brighter, even though less light was coming into his eyes.<ref name=Levelt1965>Levelt, W. J. M. (1965). Binocular brightness averaging and contour information. [[British Journal of Psychology]], 56, 1-13. https://dx.doi.org/10.1111/j.2044-8295.1965.tb00939.x</ref> This phenomenon has come to be called '''Fechner's paradox'''<!--boldface per WP:R#PLA-->.<ref>Robinson, T. R. (1896). Light intensity and depth perception. [[American Journal of Psychology]], 7, 518-532. https://dx.doi.org/10.2307/1411847</ref> It has been the subject of numerous research papers, including in the 2000s.<ref>Ding, J., & Levi, D. M. (2017). Binocular combination of luminance profiles. [[Journal of Vision]], 17(13, 4), 1-32. https://dx.doi.org/10.1167/17.13.4</ref> It occurs because the perceived brightness of the light with both eyes open is similar to the average brightness of each light viewed with one eye.<ref name=Levelt1965 />