Question

When an object is more than twenty feet from the eye and is clearly focused on the retina, the lens is ________.

1) in its roundest, most convex form
2) relaxed
3) the ciliary muscle is relaxed
4) zonular fibers of the suspensory ligament are relaxed

Answer 1

The lens is relaxed when focusing on distant objects more than twenty feet away, as the ciliary muscle is also relaxed, leading to less convexity of the lens and a more relaxed eye overall.

Step-by-step explanation:

When an object is more than twenty feet from the eye and is clearly focused on the retina, the lens is relaxed. This state occurs because the light rays from distant objects entering the eye are nearly parallel and do not require as much bending to be focused on the retina. The ciliary muscle surrounding the lens is also relaxed, which leads to a decrease in the convexity of the lens. Moreover, the zonular fibers of the suspensory ligament are tense, maintaining the lens in a relatively flat shape. In distant vision, the eye is in a state considered to be 'totally relaxed' as opposed to the 'accommodated' state required for close vision, where the lens becomes thicker and more convex to focus light on the retina.