The cornea is your window to the world. It is the outermost layer of the eye. The cornea is the dome-shaped, clear surface that covers the front portion of the eye and one of the key components of the eye in focusing light on the retina for clear vision, responsible for 65-75 percent of the eye’s total focusing power. The curvature of the cornea is important because it bends incoming light rays to focus them directly on the retina to produce a clear image. Diseases or trauma can alter the structure of the cornea, changing its curvature, thickness, or clarity, causing a loss of vision.
Unlike most tissue in the human body, the cornea does not contain the blood vessels that typical provide nourishment to the tissue or protect from infection. As an alternative, it uses nourishment from tears and a fluid in the front portion of the eye behind the cornea called the aqueous humor. Every time someone blinks, tears are created and disbursed across the cornea to keep the eye moist, and help protect against infections.
Common Issues that can occur include:
To learn more about these issues, click the links above.
The cornea may appear to be a simple structure but it is actually a very complex portion of the eye. It is composed of five layers, each serving its own function. The corneal epithelium is the outermost layer. Its primary functions are to block the passage of foreign material (bacteria, dust, etc.) into the eye, and to provide a smooth surface for absorbing oxygen and nutrients from tears and distributing them to the other layers of the cornea. The next layer, Bowman’s layer, is a transparent film of collagen. This layer can form scar tissue when injured sometimes, when a scar is large or centrally located it can affect vision. The corneal stroma is the next layer and is the thickest layer of the cornea, primarily composed of water and collagen. The shape, arrangement, and spacing of the collagen proteins crucial in producing the cornea’s light-conducting transparency. Descemet’s membrane is the next layer. It is a thin but strong layer of tissue that provides a protective barrier against injuries and infection. It can repair itself after injury. The final layer is the corneal endothelium. Its cells are important in keeping the cornea clear. The endothelium’s primary task is to pump out the excess fluid that slowly leaks into the stroma from inside the eye. Without this process, the stroma would swell, becoming thick and opaque. Endothelial cells can not be repaired or replaced by the body when they are damaged or destroyed by disease or trauma.
A healthy eye maintains a perfect balance, but as with any complex structure, there are a lot of things that can go wrong. The doctors at Kung Eye Center are experts in the field of corneal care and are equipped to treat the full range of corneal diseases and trauma. If you live in the Staten Island or East Brunswick, NJ areas come see us for all of your cornea and vision needs.
The cornea is designed to help protect your eye against dust, dirt and germs. It plays a key role in focusing light on the back of the retina, responsible for 65-75 percent of the eye’s total focusing power.