Final answer:
The retina is the tunic of the eye that converts visible light into nerve impulses, containing cells that transduce light into electrical signals.
Step-by-step explanation:
The tunic of the eye that converts visible light into nerve impulses is the retina. The retina is the innermost layer of the eye and is responsible for photoreception. It contains photoreceptive cells that transduce light into nervous impulses, which the brain can then interpret as vision. The cornea and lens work together to focus light onto the retina, while the iris adjusts the amount of light that enters the eye. Once the light reaches the retina, it is converted to electrical signals and transmitted to the brain via the optic nerve.