Light micrograph of the retina from a freshwater roach, Rutilus rutilus. The top of the photo shows the rods (thin) & cones (bulbous/purple), the light sensitive cells of the retina. The band of dense cells (bottom) is the pigment layer, beneath which is the choroid contaning blood vessels. The cones are the receptors responsible for daylight & colour vision. Rods are responsible for night or insdarkins vision. The rest of the retina (not visible) consists of layers of functionally different nerve cells. They transmit visual information as electrical signals to the ganglion nerve, which is connected to the brain. Mag: X400 (at 35mm size).