Abstract

The peak brightness in the solar spectrum is in the green only when plotted as a distribution in wavelength units It peaks in the infrared when plotted in frequency units. Therefore the oft-quoted notion that evolution lead to an optimized eye whose sensitivity peaks where there is most available sunlight or daylight is misleading and erroneous. The eye does not appear to be optimized for detection of sunlight, daylight nor for the surprisingly large amount of infra red radiation in the environment. The color sensitivity of the eye is discussed in terms of the spectral properties and the photo and chemical stabilities of the available biological materials as well as the possibility that we are viewing a souvenir of the human evolutionary voyage.

© 1997 Optical Society of America