The cornea is the clear window of the surface of the eye. It is key to the focus of the eye. The shape of this contributes towards long and short sightedness and astigmatism. This refractive error can be corrected with glasses, contact lenses or refractive laser (LASIK & LASEK) to the cornea. It is the most sensitive surface of the body.
Corneal problems cause blurring of vision. Infections or scratches cause intense pain, photophobia, redness and watering. Scratches or abrasions to the eye are invisible. If they heal poorly recurrent erosions can occur. Corneal infections, known as ulcers, are a sight threatening condition common in contact lens wearers. They are a medical emergency.
Glasses (Refractive error / Laser)
Trauma (Corneal Abrasion / Erosion)
Infection (Ulcer)
Degeneration (Dystrophy)