What is the primary function of the cornea in the eye?

The primary function of the cornea is to help focus light onto the retina. The cornea is the eye's outermost layer and serves as a transparent, dome-shaped surface that plays a crucial role in the eye's optical system. It is responsible for a significant portion of the eye’s total optical power, as it refracts or bends incoming light rays. This refraction is essential for directing light onto the retina, where images are formed and interpreted by the brain.

While the cornea does provide some degree of protection to the internal structures of the eye and serves as a barrier to dirt and pathogens, its primary role relates to light refraction and focusing. The production of tears is not a function of the cornea, rather it is performed by the lacrimal glands, which keep the eye moist and help with comfort and clarity of vision. Additionally, intraocular pressure is managed by other structures within the eye, primarily the aqueous humor and the drainage systems, rather than the cornea itself. Therefore, the corneal contribution to focusing light is fundamental to vision.