Cornea is the outermost layer of the eyeball, which is a transparent layer and act as the window to the inside part of the eyeball. Cornea structured by some cell layer and connecting collagen tissue. Cornea doesn’t have any blood vessels except in the Limbus at the side part.
The cornea's main function is to refract, or bend, light. The cornea is responsible for focusing most of the light that enters the eye. The light is received in the neural retina and optic pupil, then transmitted to the brain's neurons.
The cornea is comprised of five layers: the epithelium, Bowman's layer, the stroma, Descemet's membrane, and the endothelium. If there any damage happened in one or more layers, it’ll cause cloudiness in the cornea and causing problems with the eyesight. The cornea got it nutrition for several sources, e.g. tears, Limbus blood vessels, and the aquos from the back of the cornea. On the epithelium layer, there are free ended nerves which causing pain if there any damage in the cornea.
Some disruption or damage that may happened in the cornea:
Keratitis is an inflammation of the cornea caused by infection or non-infection, which is the most common disruption ever found. Keratitis caused by infection, usually happened because of infection by bacteria, virus, or parasite. While non-infection keratitis may happen because of immunological abnormalities on the patient, like rheumatic, eyelid inflammation, etc.
Example of things that may cause keratitis :
Complications that may happen because of keratitis :
All damage and complication on the cornea will cause temporary problems for eyesight or permanent lost of the eyesight.
Usually to fix the problem, the patients will have to undergo keratoplasty to replace the damaged cornea with a healthy one from a donor.