Optical Coherence Tomographs (IMAGE) University of California - San Diego Caption Thousands of optical coherence tomographs (OCT) form the iris and pupil of a human eye. OCTs are a non-invasive scan commonly used in clinics to diagnose diabetic retinopathy and macular degeneration. Credit Image courtesy of Daniel Kermany, Guangzhou Medical University and Kang Zhang, UC San Diego Health Usage Restrictions Use photo credit; do not change orientation of photo (vertical image) 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.