Which layer of the eye is nourished by the choroid?

The neural tunic, also known as the retina, is the layer of the eye that is nourished by the choroid. The choroid is a vascular layer situated behind the retina and contains numerous blood vessels that supply essential nutrients and oxygen to the retina. This is crucial because the retina, responsible for converting light into neural signals, requires a rich blood supply to function effectively and maintain its health.

The other layers of the eye do not receive nourishment from the choroid. For instance, the fibrous tunic, which includes the sclera and cornea, serves primarily structural and protective purposes rather than being directly nourished by choroidal blood supply. The vascular tunic consists of the choroid itself along with the ciliary body and iris, and it's primarily involved in eye color, shape, and the production of aqueous humor, rather than being the recipient of nourishment. Finally, the cornea, although it is part of the eye's structural support, has its own unique way of obtaining nutrients, predominantly from tears and the aqueous humor, rather than the choroid. Thus, the neural tunic's dependence on the choroid for nourishment is fundamental for its functionality in vision.