Final answer:
The lens is the transparent, biconvex structure in the eye that focuses light rays onto the retina. It works in conjunction with the cornea and both structures are essential for clear vision.
Step-by-step explanation:
The transparent, biconvex body behind the pupil that bends and focuses light rays is the lens. The cornea is the front transparent layer of the eye, and it works together with the lens to refract light and focus images on the retina. The iris, which is the colored part of the eye, is located between the lens and cornea, and its main function is to adjust the size of the pupil to regulate the amount of light that enters the eye. The retina contains photoreceptive cells such as rods and cones, which are crucial for sensing light and color, and ultimately for sending nerve impulses to the brain to create visual perception.