Which layer of the cornea is the innermost?

• A. Endothelium
• B. Stroma
• C. Bowman's Membrane
• D. Epithelium

Answer: (A)

The innermost layer of the cornea is the endothelium. This layer is essential for maintaining corneal clarity and overall health. The endothelium consists of a single layer of specialized cells that regulate fluid and solute movement between the cornea and the aqueous humor in the anterior chamber of the eye. This regulation is critical because it helps maintain the cornea's dehydration, which is necessary for its transparency. If the endothelium is damaged or dysfunctional, it can lead to conditions such as corneal edema, resulting in vision problems.

The stroma is the thickest layer of the cornea and provides structural integrity, while Bowman's membrane acts as a protective barrier between the stroma and the epithelium, and the epithelium is the outer layer that protects the underlying structures and provides a barrier to environmental factors. Understanding the layers of the cornea and their functions helps in comprehending various corneal diseases and the importance of endothelial health in optometry.