Which function occurs due to the ciliary body?

The ciliary body plays a crucial role in the process of focus adjustment, primarily through its control over the lens of the eye. It contains ciliary muscles that, when contracted or relaxed, alter the shape of the lens to enable the eye to focus on objects at varying distances. This process, known as accommodation, allows us to see clearly whether an object is close or far away.

While light absorption, tear production, and maintaining eye shape are important functions of the eye, they are not directly associated with the ciliary body. For instance, the cornea and other structures are more involved in light absorption, and tear production is primarily the function of the lacrimal glands. Maintaining the eye shape is largely managed by the gel-like vitreous humor and sclera, rather than the ciliary body itself. Thus, the primary and distinct function attributed to the ciliary body is indeed focus adjustment.