Stimulus modality lit area, the eyes require time for a good quantity of rhodopsin to regenerate. As more time passes, there is a higher chance that the photons will split an unbleached photopigment because the rate of regeneration will have surpassed the rate of bleaching. This is called adaptation. Humans are able to see an array of colours because light in the visible spectrum is made up of different wavelengths (from 380 to 760 nm). Our ability to see in colour is due to three different cone cells in the retina, containing three different photopigments. The three cones are each specialized to
Retina populations in the eye. AAV encoding neurotrophic factors such as fibroblast growth factor (FGF) family members and GDNF either protected photoreceptors from apoptosis or slowed down cell death. Organ transplantation Transplantation of retinas has been attempted, but without much success. At MIT, The University of Southern California, RWTH Aachen University, and the University of New South Wales, an "artificial retina" is under development: an implant which will bypass the photoreceptors of the retina and stimulate the attached nerve cells directly, with signals from a digital camera. In 1894, Santiago Ramón y Cajal published the first major characterization of retinal neurons