A corneal abrasion is a scratch on the cornea.  When there is trauma to the cornea, such as with a finger or object, the epithelium, Bowman's layer, and stroma of the cornea can be scratched, resulting in a corneal abrasion.

People with a corneal abrasion will often complain of pain and foreign body sensation. The eye will often be red.  Light sensitivity is often reported. Visual acuity may decreased slightly and possibly fluctuate.

There are may very serious maladies of the eye that have the same symptoms of eye pain, redness, sensitivity to light, and decreased vision but are not corneal abrasion.  It is very important that if you have these symptoms you be examined by an ophthalmologist.

Although the corneal surface will often rapidly heal on its own, it is very important that an ophthalmologist carefully monitor the progress of healing. You may require antibiotics for the eye or other medications.  Work closely with your eye doctor until the abrasion is healed.