Video narration
How does your eye turn light into something you can see? Like a phone camera, it lets light in and focuses it. Light enters through the clear cornea and pupil; the lens focuses it onto the retina at the back. Here's the key: the retina converts focused light into nerve signals. The optic nerve carries them to the brain, which interprets them. That's how your eye bends, focuses, and sends signals that become a picture.