Eye pain: Causes, symptoms, diagnosis and treatment

Nearly everyone suffers from eyepain or sore eyes at some point in life. Eye pain may be something that resolves on its own. It also can be a sign of something more serious.

What causes eye pain?

A feeling of discomfort or pain in the eye can be caused by a problem in the eye itself. It can also be caused by a problem involving any of the structures around the eye. The pain might stem from problems with any of the following:

• Cornea -- the clear outermost disc covering the eye that allows in focused light
• Conjunctiva -- the very thin covering of the front of the eye and inside of the eyelid
• Iris -- the coloured part of the eye, with the pupil in the middle
• Orbit or globe -- the round eyeball itself
• Muscles of the eye (extraocular muscles) -- which perform the eye's precise movements
• Nerves -- which carry visual information from the eyes to the brain
• Eyelids -- which protect and continually rub against the eyes

Problems can include:

• Corneal abrasions. The cornea is the clear disc covering the coloured part of the eye, known as the iris. The cornea is vulnerable to injuries from children's flying fingers, errant tree branches, or tennis balls. A scratch on the cornea is called an abrasion. It can be very painful.
• Corneal infections. The cornea can also become inflamed or infected, a condition called keratitis. Herpes zoster, or shingles, which is caused by the same virus that causes chickenpox, can involve the cornea.
• Conjunctivitis is inflammation of the conjunctiva, the thin lining over the front of the eye and on the inner side of the eyelids. Allergies or infections (viral or bacterial) can cause conjunctivitis. Blood vessels in the conjunctiva become engorged, and the normally white part of the eye looks red. Other symptoms usually include itchiness and discharge.
• Blepharitis occurs when there is inflammation or infection of the eyelid. A sensation of grit in the eyes, and sometimes pain, result.
• A stye -- also known as a hordeolum -- is an infection or inflammation of the eyelid margin that can come from the hair follicles of eyelashes or from oil glands. A stye is often painful and most often caused by infection.
• Foreign bodies. Sometimes there really is something in the eye -- a bit of dirt, plant debris, or a fragment of a contact lens. Foreign bodies are usually just irritating, and tears or a water rinse clears them out. If not removed, foreign bodies can cause corneal abrasions.
• Glaucoma is an eye condition that usually has no early symptoms. In some cases of glaucoma, though, pressures inside the eye rise suddenly. The condition is called acute angle closure glaucoma, and the symptoms include severe eye pain, nausea and vomiting, headache, and decreased vision. Acute angle closure glaucoma is an emergency and needs immediate treatment to prevent blindness.
• Iritis is inflammation of the iris, the coloured part of the eyeball. Iritis is uncommon, but can be due to trauma, infections, or autoimmune conditions. Symptoms include pain, red eye, and often, decreased vision.
• Optic neuritis. The nerve travelling from the back of the eyeball into the brain can become inflamed. Multiple sclerosis or other autoimmune conditions or infections are often to blame. Symptoms include eye pain and loss of vision.
• Sinusitis can create pressure behind the eyes, causing eye pain on one or both sides.