The eye is a complex organ that allows us to see. It consists of several key structures, including the cornea, which is the clear front layer that helps focus light, and the lens, which further adjusts the focus for clear vision. The retina at the back of the eye contains light-sensitive cells that convert light into electrical signals. These signals are then sent to the brain via the optic nerve, where they are processed into images. Other important parts include the iris, which controls the amount of light entering the eye, and the pupil, the opening in the center of the iris.