Which layer of the cornea consumes the most oxygen?

The layer of the cornea that consumes the most oxygen is the endothelium. This is primarily due to its role in maintaining corneal transparency and proper hydration. The endothelium is a single layer of cells that regulates fluid movement between the corneal stroma and the aqueous humor through a process of active transport. This requires a significant amount of energy, which is derived from aerobic metabolism that depends heavily on oxygen.

While other layers of the cornea, such as the epithelium, also consume oxygen for cellular metabolism and maintenance, the endothelium's active transport mechanisms and the requirement to maintain the cornea's hydration status lead to a greater oxygen uptake compared to the other layers. Consequently, the endothelium facilitates the necessary functions of the cornea while consuming the most oxygen in order to sustain these processes efficiently.