From: Proceedings of the First International Optogenetic Therapies for Vision Symposium Trans. Vis. Sci. Tech.. 2013;2(7):4. doi:10.1167/tvst.2.7.4 Figure Legend: Differential activation of an opsin molecule by lighting that appears psychophysically similar to human observers. (A) The spectral sensitivity of melanopsin, a visual pigment in the human retina that has been used as an optogenetic tool. 64,65 Shown is the principal, alpha band. 66 (B) Spectra of common, white light sources normalized to their peaks. Daylight is measured through a window on a clear day in Boston, xenon is the output of an arc lamp projected through a microscope, room light is fluorescent laboratory light, and white, light emitting diode (LED) is the beam of a flashlight. (C) Product of the spectrum of each light source with that of melanopsin. The level of melanopsin activation is obtained by integrating under the curve, and is given on the right. Date of download: 11/7/2017 The Association for Research in Vision and Ophthalmology Copyright © 2017. All rights reserved.