Corneal abrasion is a scratch or defect in the epithelium (outer layer) of the cornea. The abrasion may be caused by a small, sharp particle in the eye or by an injury – for example, by a twig or hairbrush.
Corneal abrasions usually heal quickly but may meanwhile cause severe pain and photophobia (abnormal sensitivity to bright light) and increased production of tears.
Pain may be relieved by covering the eye with a patch, by analgesic drugs (painkillers), and, if the eye muscles go into spasm, by eye-drops containing cycloplegic drugs (drugs that paralyze the ciliary muscles in the eye). Eye-drops containing antibiotic drugs are usually also given to prevent any risk of bacterial infection, which could cause serious corneal ulceration, abscess, or even blindness.
Corneal abrasions usually heal completely within a few days, but (rarely) they may recur, probably because the new epithelium fails to stick properly to the underlying tissue. Patching the eye, application of bland ointments, and even prescription of a soft "bandage" contact lens may be tried.