Which structure nourishes the retina with blood and oxygen?

The choroid is the layer of tissue located between the retina and the sclera (the white outer layer of the eyeball). It is rich in blood vessels and provides essential nutrients and oxygen to the outer layers of the retina. This nourishment is critical for the health and function of the retinal photoreceptors, which are responsible for converting light into neural signals. The choroid's dark pigmentation also helps absorb excess light, reducing glare and improving visual acuity.

In contrast, the retina itself does not provide blood supply; it relies heavily on the choroid for these vital components. The macula refers specifically to the central portion of the retina that provides sharp, detailed vision, but it, too, depends on the choroid for its blood supply. The optic nerve, while essential for transmitting visual information from the retina to the brain, does not play a role in nourishing the retina with blood and oxygen.