Light goes through the cornea first. This is the clear covering over the pupil and iris. The cornea bends the light and forms an image. The light then passes through the pupil, which is the dark circle in the center of the iris, the colored part of the eye. The pupil controls the amount of light that enters the inner eye. Then the light goes to the lens of the eye. The lens is clear and flexible and focuses an upside-down image onto the retina. When the retina senses the image, it sends impulses to the optic nerve, and the optic nerves transmits them to areas in the brain that flip the image upright.
