Certified Ophthalmic Assistant Practice Exam

The zonular fibers that support the lens are attached to which structure?

1. Iris

2. Ciliary body

3. Cornea

4. Sclera

The correct answer is: Ciliary body

The correct answer is the ciliary body, as it plays a critical role in the support and positioning of the lens in the eye. The zonular fibers, also known as zonules or fibers of Zinn, connect the ciliary body to the lens, allowing for the adjustment of lens shape during the process of accommodation. When the ciliary body contracts, it relaxes the zonular fibers, enabling the lens to become more rounded for near vision. Conversely, when the ciliary body relaxes, the tension on the zonular fibers increases, flattening the lens for distance vision. The other structures mentioned, such as the iris, cornea, and sclera, do not have a direct connection with the zonular fibers. The iris primarily functions to control the amount of light entering the eye, while the cornea is the clear front surface that helps to focus light but does not support the lens directly. The sclera serves as the protective outer layer of the eye but is not involved in the attachment of the zonules. Thus, the ciliary body is the correct structure associated with the zonular fibers.