What is the main purpose of the cornea?

The primary function of the cornea is to protect the eye while also playing a critical role in focusing light onto the retina. The cornea is a transparent, dome-shaped layer that covers the front part of the eye. This structure not only acts as a barrier against dust, debris, and harmful microorganisms, but its curvature also contributes to the eye's optical power. As light rays pass through the cornea, they are bent (refracted) to help focus the image that will ultimately be processed by the retina. Therefore, the cornea is essential for clear vision and maintaining the overall health of the eye.

The other functions mentioned, such as enhancing color perception, controlling light entry, and transmitting visual information to the brain, are performed by other parts of the eye, like the iris and the retina, making the cornea's role unique and specifically focused on protection and light refraction.