Final answer:
The white posterior section supporting the eyeball is the sclera, a part of the eye's fibrous tunic, while the vascular tunic, containing the choroid and retina, and the orbit also play key roles in eye structure and function.
Step-by-step explanation:
The white posterior section of the eye that supports the eyeball is known as the sclera. This layer, part of the fibrous tunic, provides the eye with structure and protection. Located posteriorly is the vascular tunic, which includes the choroid, supplying blood to the eye, and the retina, responsible for photoreception. The orbit, a bony socket, houses and safeguards the eyeball.
The white posterior section that supports the eyeball is called the sclera. This is part of the outermost layer of the eye, known as the fibrous tunic. The sclera is the white, tough, and fibrous tissue that forms the visible portion of the eye.