The Evolution of the Size of the Eye (IMAGE) Aarhus University Caption The evolution of the size of the eye (A) and retina (B). The evolution of structures to supplement retinal oxygen supply to tightly coupled to the evolution of large eyes and a thick retina. The pectens oculi is a vascular structure found in the eyes of birds, the choroid rete mirabile is a gas-gland found in the eyes of fishes, and intra-retinal capillaries are found in some mammals, including humans. Credit Christian Damsgaard, AU Usage Restrictions May only be used with appropriate caption and credit. 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.