Complex sentence: Eyes are the structural organs that contain the retina, a specialized type of brain tissue that contains the photoreceptors and interneurons that convert light into electrochemical signals that travel along the fibers of the optic nerve to the brain.
Split into simpler sentences: Eyes are the visual organs that have the retina, a specialized type of brain tissue composed by photoreceptors and interneurons. These specialised cells convert light into electrochemical signals that travel along the optic nerve fibers to the brain.