Corneal Abrasions and Erosion
The cornea is the clear front window of the eye. It covers the iris (colored portion of the eye) and the round pupil, much like a watch crystal covers the face of a watch. The cornea is composed of five layers. The outermost layer is called the epithelium. A corneal abrasion is an injury (a scratch, scrape or cut) to the epithelium.

Corneal erosion is a wearing away of the epithelium layer of the cornea, often at the site of an earlier abrasion. Symptoms are similar to those of a corneal abrasion: the feeling of something in your eye, pain and soreness of the eye, redness of the eye, sensitivity to light, tearing and blurred vision.

Keratoconus
Keratoconus literally means “cone-shaped cornea.” The cornea is a very important part of your eye. Light enters the eye through the cornea, which refracts, or focuses, the light rays so that you can see clearly. With keratoconus, the shape of the cornea is altered, distorting your vision.

Keratoconus usually affects both eyes, though symptoms in each eye may differ. Symptoms usually start to occur in people who are in their late teens and early twenties and may include:

• mild blurring of vision
• slight distortion of vision
• increased sensitivity to light
• glare
• mild eye irritation

The cause of keratoconus is still not known. Treatment often depends on the severity of the condition.

Pterygium and pinguecula
Pterygium (pronounced tur-IJ-ee-um) and pinguecula (pronounced pin-GWEK-yoo-la) are growths on the cornea (the clear front window of the eye) and the conjunctiva (the thin, filmy membrane that covers the white part of your eye).

Symptoms of both pterygium and pinguecula can range from mild to severe and may include:

• redness and/or inflammation — especially during the growth of a pterygium
• blurred vision
• irritation
• dryness
• itching
• burning
• gritty feeling
• feeling of having foreign material in your eye