Which property is associated with the corneal stroma?

• A. It helps maintain the cornea's transparency and avascularity
• B. It produces the tear film
• C. It contains the iris muscles
• D. It forms the lens capsule

Answer: (A)

The corneal stroma keeps the eye clear by two main features: its highly organized collagen structure and its lack of blood vessels. The collagen lamellae are arranged in precise, parallel layers with uniform fiber diameter and spacing, which minimizes light scattering and preserves transparency. Being avascular means there are no blood vessels within the stroma, so there’s no vascular light absorption or scattering that would cloud vision. Nutrients reach the stroma from the tear film and the aqueous humor, and the corneal endothelium helps maintain proper hydration to sustain this clarity. Functions like tear film production, iris muscle activity, and lens capsule formation come from other eye tissues, not the corneal stroma.