In the normal eye the ciliary muscles that control the lens will relax
A)when viewing objects at the near point.
B)when viewing objects at infinity.
C)when viewing objects at a distance of 20 ft.
D)only when a person has his/her eyes closed.

Question

Quizplus · Accepted Answer

In the normal eye, the ciliary muscles, which control the shape of the lens, will relax when viewing objects at infinity. This allows the lens to flatten out and focus light from distant objects onto the retina. When viewing objects at a closer distance, the ciliary muscles contract to make the lens more rounded and increase its refractive power. The near point is the closest distance at which the eye can focus on an object, and at this distance, the ciliary muscles are fully contracted. Therefore, option A is incorrect. Option C refers to a distance that is far enough away that the ciliary muscles are not actively accommodating, so they may be in a somewhat relaxed state, but they are not fully relaxed as they would be when viewing objects at infinity. Option D is also incorrect, as there is no need for the ciliary muscles to relax when the eyes are closed as there is no light entering the eye at that time.

In the Normal Eye the Ciliary Muscles That Control the Lens