It’s common knowledge that the eyes give us our sense of sight. But what you didn’t know is that it’s made up of a number of different parts that together form a complex system of light and electrical impulses that enable us to see. The cornea is just the first step in interpreting light as images.
The cornea is the transparent, dome-shaped window covering the front of the eye. To see the cornea, all you need to do is to look at your eye in the mirror. Looking at it closely, you’ll detect a clear thin surface covering the iris and the pupil, that’s the cornea. What does it do? What function does it serve? Together with the sclera or the white of the eye, it functions as a protective guard, a barrier against dirt, germs, and other particles that can do damage to the eye’s other delicate components. It is also responsible for 2/3 of the eyes’ focusing power. It is able to bend or refract incoming light and the curvature of the cornea will decide how well you are able to focus and how clear your vision will be. Most eye conditions like myopia (near-sightedness), hyperopia (far-sightedness) and astigmatism are caused by irregularities in the curvature of the cornea. Toric contact lenses help to correct cornea irregularities.
There are three main layers of the cornea – the epithelium, stroma and the endothelium. The epithelium is the outermost covering of the cornea. It serves to block any foreign matter from entering and damaging the cornea. In cases when the cornea sustains minor damage, it automatically regenerates the cells to repair it. It also absorbs oxygen and other nutrients from tears. This layer is extremely sensitive to pain when rubbed or scratched because of its many nerve endings. The stroma is the largest layer of the cornea, filled with 78% of water and layered protein fibers that give the cornea its elastic and solid form. Lastly, the endothelium is the single layer of cells located between the stroma and the aquaeous humor. Its primary responsibility is to remove excess water from the stroma.
It is important to care for your cornea as it can easily be damaged. Blurry vision is usually the first symptom when something is amiss with your eye. Many corneal diseases arise from infection and degeneration and a trip to the doctor is advisable as early as the first onset of symptoms.