Functions of Cornea

• It provides a physical barrier that shields the inside of the eye from germs, dust, and other harmful matter.
• It acts as the eye's outermost lens. When light strikes the cornea, it bends or refracts the incoming light onto the crystalline lens. The lens then focuses the light onto the retina, the paper-thin tissue at the back of the eye on which the image is formed.

Corneal Problems

The cornea copes very well with minor injuries or abrasions. However, if the scratch penetrates the cornea more deeply, the healing process will take longer, resulting in greater pain, blurred vision, tearing, redness, and extreme sensitivity to light. These symptoms require professional treatment. Some of the more serious problems that affect the cornea are:

Microbial Infections (Keratitis)

When the cornea is damaged, such as after a foreign object has penetrated the tissue, bacteria or fungi can pass into the cornea, causing a deep infection and inflammation. This condition may cause severe pain, reduce visual clarity, produce a corneal discharge, and perhaps erode the cornea.

As a general rule, the deeper the corneal infection, the more severe the symptoms and complications.

Conjunctivitis

This term describes a group of inflammatory and often contagious diseases of the conjunctiva (the protective membrane that lines the eyelids and covers exposed areas of the sclera, or white of the eye). These diseases can be caused by a bacterial or viral infection, drug allergy, environmental irritants, or a contact lens product. At its onset, pink eye is usually painless and does not adversely affect vision. The infection will come and go in most cases without requiring medical care. But for some forms of pink eye, such as epidemic Keratoconjunctivitis, treatment will be needed. If treatment is delayed, the infection may worsen and cause corneal inflammation and a loss of vision. Depending on the type of pink eye that a person develops, treatment often consists of antibiotics and steroids.

Ocular Herpes

Herpes of the eye is a recurrent viral infection. Extremely painful, it is very common in India. It requires regular follow up with the ophthalmologist.

Corneal scarring

Corneal scarring is by far the biggest cause of blindness in India. Due to scarring, the cornea looses its transparency thereby destroying normal vision. These scars can be the result of infections, chemical burns and injuries. In extreme cases of scarring which has led to complete visual loss, Ophthalmologist recommend a corneal transplant operation (commonly known as eye transplant). Known as Penetrating Keratoplasty, the damaged cornea is replaced by a donor "graft". The surgical process is extremely complicated.