The retina is the nerve tissue that receives focused light and begins sending visual signals toward the brain. It is a thin, light-sensitive layer lining the back of the eye, where specialized photoreceptor cells called rods and cones respond to incoming light.
The lens does not transmit nerve signals; it focuses light onto the retina. Rods are especially useful in dim conditions, while cones support color vision and fine detail. Retinal circuits process the information before retinal ganglion cells send electrical impulses through their axons.
The optic nerve then carries those impulses from the eye to the brain, where visual centers interpret them as images. This distinction explains a common mix-up: the retina converts and initially processes light, while the optic nerve provides the main physical route to the brain. The retina is considered neural tissue and develops from the embryonic forebrain, making it closely related to the central nervous system.