foreign body

When a piece of dirt, plant, or metal gets into the eye, we call this a foreign body.  Any foreign object in the eye will cause pain, watering, and occasionally an allergic response with swelling of the conjunctiva (the white part of the eye).  Debris can scratch the cornea, causing further pain and increasing the chance of infection.  The eye has more sensory nerve endings than anywhere else in the body … even after a foreign body washes out, the eye can still hurt and feel as if there is something present.  Metal foreign bodies are particularly nasty as metal pieces tend to stick to the cornea and rust into place.  All foreign bodies need to be removed before the area becomes infected.  This is done in the office at the slit lamp microscope using topical anesthesia drops – foreign body removal is a little nerve-wracking for the patient but surprisingly painless.