Rod cell Rod cell Rod cells are photoreceptor cells in the retina of the eye that can function in less intense light than the other type of visual photoreceptor, cone cells. Rods are usually found concentrated at the outer edges of the retina and are used in peripheral vision. On average, there are approximately 90 million rod cells in the human retina. Rod cells are more sensitive than cone cells and are almost entirely responsible for night vision. However, rods have little role in color vision, which is the main reason why colors are much less apparent in dim light, and not
Giant retinal ganglion cells Giant retinal ganglion cells Giant retinal ganglion cells are photosensitive ganglion cells with large dendritic trees discovered in the human and macaque retina by Dacey "et al". (2005). Giant retinal ganglion cells contain a photo-pigment, melanopsin, allowing them to respond directly to light. They also receive connections from rods and cones, allowing them to encode colour and spatial information. Dacey "et al". found the giants' receptive field sizes to be about three times the diameter of those of parasol ganglion cells. There are only about 3000 giant retinal ganglion cells in each retina, comprising about 0.2% of the total number