Which of the following structures in the eye is NOT innervated by the parasympathetic system?

The choroid is a layer of tissue located between the retina and the sclera, primarily responsible for providing oxygen and nutrients to the outer layers of the retina, as well as absorbing excess light to prevent reflection within the eye. Unlike the ciliary muscle, iris, and lacrimal gland, which are innervated by the parasympathetic nervous system, the choroid does not receive direct parasympathetic innervation.

The ciliary muscle is innervated by parasympathetic fibers, allowing for accommodation of the lens during near vision. The iris, particularly its sphincter muscle, is also controlled by the parasympathetic system to constrict the pupil in response to bright light conditions. Additionally, the lacrimal gland receives parasympathetic stimulation for tear production, which is essential for keeping the ocular surface moist and comfortable. In contrast, the choroid's functions are primarily related to its structural and vascular role rather than being actively regulated by the parasympathetic nervous system.