Cornea

The cornea is the clear tissue at the front and center of the eye. Its clarity (translucence) permits light to pass into the eye, through the pupil and on to the retina at the back of the eye. Its curvature focuses (refracts) the light.

Symptoms:

Blurred vision occurs whenever a disease affects either the clarity or the curvature of the cornea. Pain, sometimes quite severe, occurs if the illness affects the nerves in and near the cornea. Trauma resulting in cuts or abrasions of the cornea may also cause pain. Irritation and light sensitivity are common symptoms in many disorders affecting the surface of the cornea.

What are the different types of corneal disease?:

There are several conditions that can affect the cornea, including infections (such as bacterial or viral keratitis), trauma, genetic disorders, degenerative disorders, autoimmune disorders, nutrition deficiencies, allergies, dystrophies and ectatic disorders (such as keratoconus), inflammatory diseases, and growths. The cornea can also be damaged secondarily by other eye conditions such as tear film abnormalities and dry eye, eyelid disorders, and glaucoma.

When Do You Need a Cornea Transplant?:

A healthy, clear cornea is essential for good vision. If your cornea is damaged due to eye disease or eye injury, it can become swollen, scarred or severely misshapen and distort your vision. A cornea transplant may be necessary if eyeglasses or contact lenses can't restore your functional vision, or if painful swelling can't be relieved by medications or special contact lenses. Certain conditions can affect the clarity of your cornea and put you at greater risk of corneal failure. These include:
1.Scarring from infections, such as eye herpes or fungal keratitis.
2. Hereditary conditions such as Fuchs' dystrophy.
3. Eye diseases such as advanced keratoconus.
4. Thinning of the cornea and irregular corneal shape (such as with keratoconus).
5. Rare complications from LASIK surgery.
6. Chemical burns of the cornea or damage from an eye injury.
7. Excessive swelling (edema) of the cornea.
8. Graft rejection following a previous corneal transplant.
9. Corneal failure due to cataract surgery complications.