Superior view of the brain revealing the visual pathway and superior sagittal sinus. Electrical nerve impulses travel from the eyes to the occipital lobe in the back of the brain via millions of nerves fibers that make up the visual pathway.
Optic nerve fibres. Coloured scanning electron micrograph (SEM) of axons from the optic nerve. Connective tissue fibres (thread-like) are also visible. The optic nerve visual information from the retina in the eye to the brain. Magnification: x2000 when printed at 10 centimetres wide.
Rods and cones in retina: colourized scanning electron micrograph (SEM) of rods and cones, showing the structure of the eye retina. Rods (green) are long nerve cells which respond to dim light, enabling images to be detected. Cones (blue) are shorter cone-like cells which detect colour. Rods and cones pass visual signals through the optic nerve to the brain. Pigment cells block light from passing further. Magnification: unknown.
Retina close up cross section | The retina is the innermost layer of the eye and is composed of several layers of neurons interconnected by synapses. The only neurons that are directly sensitive to light are the photoreceptor cells, rods and cones. Light energy creates an image of the visual world on the retina, triggering nerve impulses that are sent to the visual centers of the brain through the optic nerve.
Retina. SEM of a section through a human retina, the light-sensitive tissue that lines the inside of the eye. Light entering the eye passes through several layers of cells before reaching the light receptors. From top to bottom are seen: cell bodies of optical ganglion cells (pale red), which form the optic nerve; cell bodies of bipolar neurons and cell bodies of the receptor cells (red); and the rod (white) and cone (yellow) receptors.