Photoreceptor Distribution in Retina PDF

o MORE RODS THAN CONES (each eye has 120M rods vs. 6M cones or 20x more rods than cones.) More important to see light than detail initially! o Cones are concentrated in the fovea. Rodsford in Peripher o Rods are 1000x more sensitive to light than cones. Better at detecting light – telling us whether...

o MORE RODS THAN CONES (each eye has 120M rods vs. 6M cones or 20x more rods than cones.) More important to see light than detail initially! o Cones are concentrated in the fovea. Rodsford in Peripher o Rods are 1000x more sensitive to light than cones. Better at detecting light – telling us whether light is present i.e. black/white vision. o Cones detect color primarily but also some light (three types : 60% Red, 30% Green, 10% Blue) o Rods have slow recovery time vs. cones have fast recovery time. Takes a while to adjust to dark – rods need to be reactivated. Cones adapt to change quickly (fire more frequently) a recovery tim T Photoreceptor Distribution in Retina • • • • Where optic nerve connects to retina, blind spot – no cones or rods. Rods are found mostly in periphery. Cones are found primarily in the fovea, and few dispersed through the rest of eye. At the fovea (dimple in retina) - there no axons in way of light so get higher resolution. At the periphery - light has to go through bundle of axons and some energy lost. So at fovea light hits cones directly. At the periphery, less light gets to the rods. & 24