Mini Retina (IMAGE) Johns Hopkins Medicine Caption These are rod photoreceptors (in green) within a "mini retina" derived from human iPS cells in the lab. Credit Image courtesy of Johns Hopkins Medicine 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.