The cornea's two primary functions are protecting the eye and refracting light.
Here's a breakdown of these crucial roles:
Protection
The cornea acts as the eye's first line of defense against:
- Physical damage: It shields the delicate inner structures from injury caused by dust, debris, and other external objects.
- Infection: It provides a barrier against bacteria, viruses, and fungi that could cause eye infections.
- Ultraviolet (UV) radiation: It filters out some harmful UV rays, reducing the risk of UV-related eye damage.
Refraction
The cornea plays a vital role in vision by:
- Bending light: It is responsible for approximately 65-75% of the eye's total refractive power. This bending of light is essential for focusing images onto the retina. Think of it as the eye's initial lens.
- Working with the lens: The cornea performs the initial refraction, and then the lens further refines the focus of the light onto the retina, allowing for clear vision at varying distances.
In short, the cornea not only guards the eye from external threats but also begins the crucial process of focusing light, which is essential for sight.
