The Retina (image) NIH/National Eye Institute Share Print E-Mail Caption An artist's rendering of neural activity in the retina is shown. Light that enters the eye activates rod and cone photoreceptors, which in turn activate retinal ganglion cells. Signals travel to the brain via retinal ganglion cell axons. Credit National Eye Institute Usage Restrictions Photo credit: National Eye Institute Share Print E-Mail 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.