What role does the ciliary body play in eye function?

The ciliary body plays a crucial role in the production of aqueous humor, which is the clear fluid found in the anterior chamber of the eye. This fluid is essential for maintaining intraocular pressure and providing nutrients to the avascular structures of the eye, such as the lens and cornea. The aqueous humor flows from the posterior chamber, through the pupil, into the anterior chamber, where it is eventually drained through the trabecular meshwork.

The ciliary body is also involved in regulating the shape of the lens through the action of ciliary muscles, which helps control focus for near and distant vision. However, in the context of this question, the primary and most direct function of the ciliary body is the production of aqueous humor, which is critical for maintaining ocular health and proper eye function.

While other options may relate to functions of different structures in the eye or additional roles of the ciliary body, the specific contribution of aqueous humor production is essential for understanding the importance of the ciliary body in overall eye physiology and function.