Human eye Human eye The human eye is an organ which reacts to light and pressure. As a sense organ, the mammalian eye allows vision. Human eyes help to provide a three dimensional, moving image, normally coloured in daylight. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth. The human eye can differentiate between about 10 million colors and is possibly capable of detecting a single photon. Similar to the eyes of other mammals, the human eye's non-image-forming photosensitive ganglion cells in the retina receive light signals which affect adjustment
Retina horizontal cell that separate them. Mosaic arrangements provide a mechanism to distribute each cell type evenly across the retina, ensuring that all parts of the visual field have access to a full set of processing elements. MEGF10 and MEGF11 transmembrane proteins have critical roles in the formation of the mosaics by horizontal cells and starburst amacrine cells in mice. Horizontal cells are depolarized by the release of glutamate from photoreceptors, which happens in the absence of light. Depolarization of a horizontal cell causes it to hyperpolarize nearby photoreceptors. Conversely, in the light a photoreceptor releases less glutamate, which hyperpolarizes the horizontal cell,