The retina is a thin layer of tissue that lines the back of the eye on the inside. It is located near the optical nerve. The purpose of the retina is to receive light focused from the lens, convert the light into neural signals, and send these signals on to the brain. The retina processes light through a layer of photoreceptor cells. These are essentially light-sensitive cells, responsible for detecting qualities such as colour and light-intensity. The retina processes the information gathered by the photoreceptor cells and sends this information to the brain via the optic nerve. Essentially, the retina processes a picture from the focused light, and the brain is left to decide what the picture is. Due to the retina's vital role in vision, damage to the retina can cause permanent blindness. Conditions such as retinal detachment, where the retina is abnormally moved from its usual position, can prevent the retina from receiving or processing light, and therefore prevents the brain from receiving this information, thus causing blindness.
Written and medically reviewed by the Healthline Editorial Team
In Depth: Retina