The cornea is the clear, dome-shaped outer layer of the eye that covers the iris, pupil, and anterior chamber. It functions as the eye's primary focusing surface, helping to bend and refract light onto the retina to enable clear vision. Composed of five layers, the cornea is both strong and flexible, providing protection against dirt, germs, and other harmful particles. Its transparency is crucial for vision, as it allows light to pass through without distortion. Damage or disease affecting the cornea, such as keratitis or corneal dystrophies, can result in blurred vision or blindness. Treatments for corneal issues range from medications and contact lenses to surgical procedures like corneal transplants, depending on the severity of the condition.