Muhammad Ali brushes a tear from his eye as he congratulates his sister-in-law Sandra Pickett Ali, on her graduation from nursing school in Chicago Oct. 3, 1966. Her husband, Ali's brother, Rahaman, smiles happily at the commencement exercises. UPI
The retina is located in the innermost layer of the eye and senses light. Rod cells in the retina supply vision in low light, while cone cells in the retina supply color and detail to vision. Find more eye anatomy facts on this Chicago eye surgeon infographic.