The cornea is the outermost layer of the eye in the form of a dome-shaped clear membrane, which covers the front of the eye. The role of the cornea is very important for vision. Each part of the cornea of the eye has its own function, but supports each other.
Unlike other body tissues, the cornea does not have blood vessels. The function of the blood vessels in the cornea is replaced by tears and aqueous humor (clear slimy fluid in the eye). Cornea is a tissue that is sensitive or sensitive to stimulation, because it is the part of the body that is the most traversed by nervous tissue.
Know the Functions of the Cornea and Its Various Parts
The main function of the cornea is to refract (bend) and focus the light that enters the eye. In the process of seeing, incoming light needs to be refracted by the cornea into the eye lens, then forwarded to the retina.
On the retina, light is converted into electrical impulses to be transmitted to the brain, where it is translated into images. If the eye is like a camera, then the cornea is part of the camera lens.
The cornea also has another function, namely protecting the eye from foreign particles (germs or dirt) and exposure to ultraviolet light that can harm the eye.
To perform these various functions, the cornea has five parts, namely:
1. Epithelial tissue
Epithelial tissue is the outermost layer of the cornea that serves to protect the eye from foreign particles, such as dust, water, or bacteria. The sclera, or the white part of the eye, helps with this function. Epithelial tissue is also a soft textured surface, similar to gelatin, which can absorb oxygen and nutrients from tears for the cornea.
In this network, there are thousands of nerve endings. Therefore, you can feel pain if your eye is scratched or rubbed too hard. These nerve endings are also what help the corneal reflex, or better known as the blink reflex, occur when the eye is exposed to a foreign object.
2. Bowman's Layer
After the epithelial tissue, there is a transparent membrane made of collagen. This membrane is called Bowman's layer and serves to maintain the shape of the cornea.
This layer has no regenerative (self-renewal) ability, so an injury to this area will result in permanent scarring or scarring. If the scar is large enough, your vision may be impaired.
3. Stroma
The stroma is the thickest layer of the cornea, just behind Bowman's layer. This layer is composed of water and collagen and is the area of refraction of light on the cornea. Therefore, it is important to keep the stroma transparent and translucent.
In addition, the stroma also functions to maintain the shape of the cornea so that it remains elastic, dense, and strong.
4. Membrane descemet
membrane descemet It is the thinnest and strongest tissue in the cornea. This membrane is made of collagen and serves as a resting place for endothelial cells while protecting them from infection and injury.
membrane descemet has good self-recovery abilities, so it is easy to recover after an injury.
5. Endothelial layer
The endothelial layer is a single, thin layer that lies in the deepest part of the cornea and is in direct contact with the aqueous humor. This layer keeps the cornea clear and regulates the water content of the eye by absorbing water from the stroma.
The cornea is a very important part of the eye. Therefore, the health of the cornea needs to be maintained properly, in order to avoid visual disturbances due to diseases of the cornea. If the cornea is affected by certain diseases, such as infections, then this condition can cause the eyes to experience visual disturbances.
If you have eye complaints, such as watery eyes, redness, sensitivity to light, and cloudy or blurry vision, you should immediately consult an ophthalmologist so that they can be treated appropriately.