Final answer:
The sun is essential for vision because it provides the light that allows us to see. Light from the sun enters our eyes and is focused onto the retina, where it is converted into signals sent to the brain for interpretation.
Step-by-step explanation:
The sun plays a critical role in our ability to perceive the world through vision. The primary way it does so is by emitting light, which is essential for sight. Specifically, in regards to the question presented, the correct response is option 3: It shines light on objects, allowing us to see. The process of sight begins when light enters the eye through the cornea, passes through the pupil, and is focused by the lens onto the retina. The retina, which contains light receptor cells, then converts light into nerve impulses that are sent to the brain. The brain interprets these impulses and enables us to understand what we are seeing. Therefore, the role of the sun in vision is intrinsic to the entire process of seeing, as it is our primary natural source of light.