Which structure functions as the protective outer layer of the eyeball?

• A. Pupil
• B. Sclera
• C. Retina
• D. Cochlea

Answer: (B)

The outer protective layer of the eyeball is the tough, white coat that encases most of the eye. This dense connective tissue forms the sclera, which provides shape and safeguards the internal structures. It’s the opaque covering you see around the iris and is designed to resist bending and damage, while the front of the eye has the cornea, a transparent window that lets light in. The sclera also serves as the attachment point for the eye muscles that move the eyeball. The pupil is an opening in the iris that regulates light entry, the retina lines the inner surface and detects light, and the cochlea is part of the inner ear—unrelated to the eye.