What is the primary purpose of the tarsus?

The primary purpose of the tarsus is to support eyelid structure. The tarsus is a dense, plate-like structure composed of connective tissue, found within the eyelids of both animals and humans. This structure provides rigidity and strength to the eyelids, allowing them to maintain their shape and function effectively. By supporting the eyelid, the tarsus plays a vital role in ensuring that the eyelids can close properly, which is essential for protecting the eye and maintaining moisture on the eye surface.

While tear drainage, lubrication, and protection of the eyeball are important functions associated with other components of the eye and eyelid system, they do not specifically pertain to the primary role of the tarsus. For instance, the drainage of tears is primarily facilitated by the lacrimal system, while protection involves multiple layers, including the eyelids and eyelashes, working together to shield the eyeball.