Which part of the eye connects the cornea to the sclera?

The limbus is the correct answer because it serves as the anatomical junction between the cornea and the sclera. The limbus is a narrow band situated at the border where the clear cornea transitions into the opaque sclera, and it plays a crucial role in the overall structure of the eye. It contains stem cells that are essential for the regeneration of corneal epithelial cells, helping maintain corneal health and integrity.

The other options do not represent the connection between the cornea and the sclera. The macula is an area of the retina responsible for central vision, not involved in the structural connection between the cornea and sclera. The posterior chamber is an anatomical space filled with aqueous humor, located behind the iris and in front of the lens, which again does not pertain to the connection of the cornea and sclera. The optic disk, where the optic nerve exits the eye, does not relate to the corneal-scleral junction either. Thus, the limbus is clearly defined as the structure connecting these two parts of the eye.