Final answer:
The lens of the eye must be less powerful, or flatter, to focus light from distant objects onto the retina. This occurs because light rays from distant objects are parallel and require less bending. In contrast, light rays from close objects require the lens to be more powerful and thicker to converge on the retina.
Step-by-step explanation:
The question relates to how the human eye focuses light to form images on the retina, and specifically pertains to the accommodation of the eye for vision of distant objects. Light rays from distant objects are nearly parallel when they enter the eye, and the eye's lens must adjust to properly focus these light rays onto the retina. For distant vision, the lens needs to be less powerful, or thinner, because the parallel light rays do not require much bending to meet at the focal point on the retina. This is in contrast to close vision, where the lens must be more powerful and thicker to converge the diverging light rays from nearby objects onto the retina.
When looking at distant objects, the eye is in a relaxed state, the ciliary muscles are relaxed, and the lens flattens. This is described as the eye being 'totally relaxed'. In effect, this makes the lens less converging as compared to when it is accommodating for close vision. Thus, the lens needs to be flatter when focusing on distant objects.