Light is changed into sight by converting light into electrical stimuli. These electrical impulses are sent from the retina to the brain and are interpreted as images. The retina is membrane lines the inside wall of the eye which consists of 5 main cells: photoreceptors (rods & cones), horizontal cells, bipolar cells ("on" and "off" cells) which connect photoreceptors to retinal ganglion cells, amacrine cells, and ganglion cells which are the last neurons before the optic nerve (actually, the axons of ganglions make up the optic nerve).
The ganglion cell collects the electrical messages concerning the visual signal from the two layers of nerve cells preceding it in the retinal wiring scheme. The ganglion cell represents the ultimate signaller to the brain for retinal information. Ganglion cells transmit signals (via electrical pathways) to the brain, with a small amount of calcium flow into the cell. Ganglion cells are larger on average than most preceding retinal interneurons and have large diameter axons capable of pass
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