Morgridge Institute for Research Mar 13 2025 Inside the human eye, the retina is made up of several types of cells, including the light-sensing photoreceptors that initiate the cascade of events that lead to vision. Damage to the photoreceptors, either through degenerative disease or injury, leads to permanent vision impairment or blindness.  David Gamm, director of UW–Madison's McPherson Eye Research Institute and professor of ophthalmology and visual sciences, says that stem cell replacement