How are corneal stromal collagen lamellae arranged to maintain transparency?

• A. Randomly oriented in all directions
• B. Multiple collagen lamellae arranged regularly and run in alternating directions
• C. A single thick lamella in the center
• D. Parallel lamellae all in the same direction

Answer: (B)

The cornea stays transparent because its stroma is made of many collagen lamellae that lie close to the surface and are arranged in multiple layers, with each layer running in a different direction from the one above or below. This regular, alternating orientation creates a lattice-like, crosswise pattern that keeps the spacing and refractive properties consistent across the stroma, minimizing light scattering as it passes through. If the lamellae were randomly oriented, light would scatter more; a single thick lamella would fail to provide the multi-directional optical uniformity needed; and all lamellae in the same direction would introduce directional differences that disrupt transparency.