The cornea, a critical component of the eye, must be transparent to visible light and have the correct refractive power to focus images accurately. These properties are governed by its structural organization. Transparency results from the constructive interference of light due to the ordered arrangement of collagen fibrils in the corneal stroma, which is controlled by negatively charged proteoglycans. Small changes in fibril organization can be tolerated, but larger changes cause light scattering. Corneal keratocytes do not scatter light because their refractive index matches that of the surrounding matrix. However, when activated, they become fibroblasts with a lower refractive index, increasing light scatter. The corneal stroma has a lamellar structure, with parallel collagen fibrils within each lamella making a large angle with those of adjacent lamellae. X-ray scattering shows preferred orientations of these lamellae in the human cornea. Elastic fibers are also present, with different arrangements in the limbus and central cornea. A model based on these structural features explains how the cornea withstands repeated pressure changes due to the ocular pulse, maintaining its transparency and refractive power.The cornea, a critical component of the eye, must be transparent to visible light and have the correct refractive power to focus images accurately. These properties are governed by its structural organization. Transparency results from the constructive interference of light due to the ordered arrangement of collagen fibrils in the corneal stroma, which is controlled by negatively charged proteoglycans. Small changes in fibril organization can be tolerated, but larger changes cause light scattering. Corneal keratocytes do not scatter light because their refractive index matches that of the surrounding matrix. However, when activated, they become fibroblasts with a lower refractive index, increasing light scatter. The corneal stroma has a lamellar structure, with parallel collagen fibrils within each lamella making a large angle with those of adjacent lamellae. X-ray scattering shows preferred orientations of these lamellae in the human cornea. Elastic fibers are also present, with different arrangements in the limbus and central cornea. A model based on these structural features explains how the cornea withstands repeated pressure changes due to the ocular pulse, maintaining its transparency and refractive power.