Which is the correct anterior-to-posterior order of the corneal layers from front to back?

• A. Epithelium; Bowman's layer; Stroma; Descemet's membrane; Endothelium
• B. Bowman’s layer; Epithelium; Stroma; Descemet's membrane; Endothelium
• C. Epithelium; Bowman's layer; Stroma; Endothelium; Descemet's membrane
• D. Epithelium; Stroma; Bowman's layer; Descemet's membrane; Endothelium

Answer: (A)

The correct sequence is the front to back arrangement of the corneal layers: Epithelium, Bowman's layer, Stroma, Descemet's membrane, Endothelium. The epithelium is the outermost surface, followed by Bowman's layer, a tough acellular sheet. Beneath that lies the thick stroma, which makes up most of the cornea's thickness. Posterior to the stroma is Descemet's membrane, a basement-like layer secreted by the endothelium. The innermost layer facing the anterior chamber is the endothelium, a single cell layer that regulates corneal hydration. This arrangement places Descemet's membrane immediately anterior to the endothelium, not after it, and keeps Bowman's layer between the epithelium and the stroma.