The densely packed mosaic of cone photoreceptor cells in the foveal center of a human eye, overlaid with letters used to test visual acuity. Color indicates cell density. (IMAGE)

Universitatsklinikum Bonn

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.