The cornea is the clear front window of the eye. It bends incoming light so it focuses sharply on the retina, allowing clear vision.
What the cornea does
The cornea has several thin layers that must remain clear and smooth. Tiny nerves make it very sensitive, which helps protect the eye from harm.
- The outer epithelium acts as a barrier against dust, germs, and minor injuries.
- The middle stroma provides strength and must stay precisely organised to stay clear.
- The inner endothelium pumps out extra fluid to prevent corneal swelling.
- Even slight irregularities can cause blurred or distorted vision.
- Healthy tears are essential to keep the corneal surface smooth.
Common corneal problems
Infections, injuries, dry eye, and conditions like keratoconus can affect the cornea. Symptoms often include pain, light sensitivity, watering, and blurred vision.
- Minor scratches usually heal quickly but may feel very painful.
- Contact lens overwear increases the risk of corneal infection.
- Keratoconus causes the cornea to become thinner and cone-shaped over time.
- Treatments range from drops and bandage lenses to cross-linking or transplant.
- Any sudden painful red eye or drop in vision needs urgent specialist review.
