In the world of ocular biology, the cornea is a star. So small and transparent, it is of vital importance to human vision. But what exactly is the cornea? And how does it work? Let's delve into the mysteries of this organ. 

What is the cornea?

Think of the cornea as the window in your home through which you observe the outside world. The cornea is the outer, transparent layer of the eye, located in front of the iris, the coloured part of the eye. It's the eye's first lens that comes into contact with light. It's on the cornea that you place your contact lens.

Structure of the cornea

The cornea comprises several layers of transparent tissue, organized in a complex way to ensure the optical clarity necessary for vision. These layers include the epithelium, stroma and endothelium.

  • Epithelium: The cornea's outermost layer, the epithelium, acts as a protective barrier against damage and infection. It is also responsible for regulating corneal hydration.
  • Stroma: This is the thickest layer of the cornea, representing around 90% of its total thickness. The stroma is made up of precisely organized collagen fibres, which give it its transparency. This transparency is essential to allow light to pass through the cornea without being diffused.
  • Endothelium: This layer is located at the back of the cornea, in contact with the liquid inside the eye (the aqueous humour). The endothelium regulates the amount of fluid in the cornea, helping to maintain its optical clarity.

Function of the cornea

The cornea's primary function is to act as a converging lens, which means it focuses light entering the eye to form a sharp image on the retina. The cornea's ability to refract light is essential for clear, sharp vision. 

Common corneal problems

Unfortunately, the cornea is not immune to problems. Conditions such as corneal ulcers, corneal opacities, keratoconus, and dry eye can affect the clarity and health of the cornea, resulting in blurred vision, pain, and sensitivity to light. Faced with such conditions, it is essential to consult an eye health professional for appropriate treatment. 

Treatment of corneal problems

Fortunately, many corneal problems can be successfully treated. Treatment options range from topical medications and special contact lenses to surgical procedures such as corneal transplants and laser surgery.

The cornea, while seemingly simple at first glance, is, in fact, a complex organ essential for clear, sharp vision. By understanding its structure and function, we can better appreciate the importance of caring for our eyes and protecting the health of our corneas.