The term "retinal" refers to anything related to the retina, which is the light-sensitive layer of tissue located at the back of the eye. The retina plays a crucial role in vision by converting light into electrical signals that are sent to the brain for processing. Retinal can also refer to a specific chemical compound, known as retinaldehyde, which is essential for the function of photoreceptor cells in the retina. These cells, including rods and cones, help us perceive light and color, making retinal vital for our ability to see.