Which part of the eye helps in the proper focusing of images onto the retina?

The lens plays a crucial role in the proper focusing of images onto the retina. Located just behind the iris and pupil, the lens is a transparent structure that adjusts its shape to focus light rays accurately onto the retina. This process is known as accommodation. When looking at objects at different distances, the lens changes curvature; it becomes thicker to focus on closer objects and flattens for distant objects, ensuring that the image is sharply focused on the retina’s surface.

The other components mentioned, while also important to vision, have different functions. The ciliary body is responsible for controlling the shape of the lens via the zonules, the iris regulates the amount of light entering the eye by adjusting the size of the pupil, and the cornea provides most of the eye's optical power but does not adjust focus like the lens. Understanding these distinctions emphasizes the importance of the lens in vision and image processing within the eye.