Human Retina (IMAGE) Duke University Caption A composite image of the human retina shows diffused pigmentary retinal degeneration. Credit Ziqiang Guan, Duke University Medical Center Usage Restrictions Please credit Ziqiang Guan, Duke University Medical Center 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.