Eyes are complicated, containing numerous parts that must work together harmoniously in order for you to enjoy good vision. Light enters through the pupil, and the iris controls how much light can enter. After passing through the lens, light hits the retina and cells known as photoreceptors transform the light into electrical signals. These electrical signals travel through the optic nerve to reach the brain, which turns those signals into images. Make sense? However, we left out one piece of the puzzle in that explanation: the cornea. What does the cornea do?
What Does the Cornea Do?
The cornea is sometimes called the “window” of the eye. Made of tough but transparent tissue, it’s located on the front of your eye and it’s shaped like a dome. The cornea plays two important roles: (1) it helps you see and (2) it protects your eye from contaminants.
Let’s start with the role the cornea plays in vision. As light enters the eye, the curved edge of the cornea refracts (or bends) that light, which helps the eye to focus. It ensures that your eye can focus on objects that are close-up as well as those that are far away. A healthy cornea supports good vision, but if your cornea is damaged through disease, infection, or injury, any resulting scars can negatively impact your vision. They may block or distort the light entering the eye, causing you to have poor eyesight.
Now let’s look at the protection provided by the cornea. Along with the eyelids, eye sockets, tears, and sclera (the white of your eye), the cornea acts as a barrier, protecting the eye from dirt, debris, germs, and other potentially dangerous contaminants. In fact, the cornea even filters out some ultraviolet (UV) light when you’re out in the sunshine! The amount of UV protection provided by the cornea is minimal, however, so it’s still important that you wear sunglasses that protect against both UVA and UVB rays.
The Layers of the Cornea
To better understand how the cornea works, you might find it helpful to learn the three primary layers of the cornea:
- The outermost layer of the cornea, known as the epithelium, acts as a barrier, protecting against dirt, dust, debris, and other outside matter. It also helps your eye absorb oxygen and nutrients from tears.
- Connected to the epithelium by Bowman’s layer, the stroma is the thickest layer of the cornea. It is composed of water and protein, giving it a solid but stretchy structure. The stroma provides the cornea with its integral domed shape.
- Separated from the stroma by Descemet’s layer, the endothelium is a single layer of cells found in front of the aqueous humor (or the clear fluid at the front of the eye). This layer removes extra water that cannot be absorbed by the stroma. If the endothelium did not perform this pump-like function, the stroma would become waterlogged and your vision would become hazy.
Now that you better understand how the eye works and the cornea’s role in the process, it’s time to ask yourself a very important question: When’s the last time you had your eyes checked?
If you’re overdue for an eye exam and you live in southwest Missouri, stop by Heffington’s. Since 1975, the Heffington family has been assisting the Springfield community with top-quality eye care and affordable eyeglasses and contacts. One of the unique features of our family-owned business is that we manufacture lenses at our own laboratory, giving us total control over the service and pricing, and we’re happy to pass our savings on to you. To learn more about our products and services, please get in touch with us online, send an e-mail to [email protected], or give us a call at 417-869-3937 (Optiland location) or 417-882-3937 (House of Vision location). We look forward to hearing from you!