What is the primary function of the cornea?

The primary function of the cornea is to provide optical power to the eye. It is a transparent, dome-shaped structure at the front of the eye that helps to focus light onto the retina, which is essential for clear vision. The cornea refracts, or bends, light rays as they enter the eye, contributing approximately two-thirds of the eye's total optical power. This bending of light is vital for proper visual acuity.

Other options, while related to eye function, do not accurately represent the main role of the cornea. The cornea does not act as a storage site for nutrients or merely serve to cover the pupil; instead, these roles are associated with other structures in the eye. While the cornea does play a part in separating the anterior and posterior chambers of the eye, this is not its primary function. The cornea's main role is fundamentally linked to vision by refracting light, which is why the correct answer highlights its optical power provision.