Rods and Cones (IMAGE) University of Arizona College of Engineering Caption Rod (green) and cone (red) photoreceptors in a human retina. Credit Dr. Robert Fariss, National Eye Institute, NIH Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.