What are the three layers that make up the walls of the eyeball?

The three layers that comprise the walls of the eyeball are known as the fibrous, vascular, and nervous tunics. This classification reflects the anatomical organization of the eye, where each tunic has distinct functions.

The outer layer is the fibrous tunic, which includes the cornea and sclera. It provides structural support and protection. The middle layer is the vascular tunic, also known as the uvea, consisting of the choroid, ciliary body, and iris; it contains blood vessels and is important for nourishing the eye as well as regulating light entry. Lastly, the inner layer is the nervous tunic, which is primarily the retina; this layer is crucial for detecting light and converting it into neural signals that the brain interprets as vision.

This classification system is clinically significant, as it helps in understanding various eye conditions and their relation to these structural components. Other options, while they may refer to parts of the eye, do not accurately represent the comprehensive layers that form the eyeball's walls. For example, the cornea and sclera are part of the fibrous tunic, and the retina is just one part of the nervous tunic, while the conjunctiva does not form part of the eyeb