Certified Surgical Technologist (CST) Practice Exam

The fibrous white layer that gives the eye its shape is the:

1. Iris

2. Cornea

3. Sclera

4. Choroid

The correct answer is: Sclera

The sclera is the correct answer because it serves as the protective outer covering of the eye. This fibrous tissue is composed primarily of collagen and provides structural support, enabling the eye to maintain its shape. The sclera is continuous with the cornea at the front of the eye. It also plays a crucial role in attachment for the eye muscles that control movement. In contrast, the iris is the colored part of the eye that regulates the amount of light entering through the pupil. The cornea is the transparent front part of the eye that allows light to enter and focuses it onto the retina, but it does not provide the same structural integrity as the sclera. The choroid is the vascular layer of the eye containing connective tissue and blood vessels and is located between the sclera and the retina but does not contribute to the shape of the eye in the same way the sclera does.