The white protective layer on the outside of the eyeball is known as what?

The white protective layer on the outside of the eyeball is known as the sclera. The sclera serves as a tough protective covering for the inner components of the eye and maintains its shape. It is made of dense connective tissue, which provides both support and protection. This outer layer also serves as an attachment point for the muscles that move the eye, facilitating eye movement.

The other structures mentioned in the choices have different functions: the retina is responsible for converting light into neural signals; the cortex typically refers to the outer layer of an organ or structure, often mentioned in the context of the brain or kidneys; and the cornea is the transparent front part of the eye that covers the iris and pupil, playing a crucial role in focusing light. Understanding these distinctions enhances comprehension of the eye's anatomy and functions.