Pain in the eye and around the eye can have many causes. In some cases, such as an eye injury, the cause of the pain is obvious. But often it is difficult to know why your eye hurts.
To complicate matters, the severity of eye pain does not indicate how serious the underlying cause of the discomfort is. In other words, a relatively minor problem, such as a superficial abrasion of the cornea, can be very painful. But several very serious eye conditions — including cataracts, macular degeneration, the most common type of glaucoma, a detached retina, and diabetic eye disease — cause no eye pain whatsoever.
The cornea of the eye is among the most sensitive tissues of the body. In fact, the density of sensory nerves in the cornea can be up to 500 times that of the skin.
The high sensitivity of the cornea is useful, because it’s the first line of defense against external injury to the eye. So if something irritates the front surface of your eye, you will notice it quickly.
A painful eye can produce various sensations and accompanying symptoms, which can help your eye doctor determine the cause of your discomfort. These include a sharp, stabbing sensation, a burning sensation, throbbing, a dull ache, and a feeling something is “in” your eye (this is called a “foreign body sensation”).
Eye pain also is frequently accompanied by blurred vision, redness (bloodshot eyes) and sensitivity to light.
Here are common causes of eye pain, based on the location of the discomfort:
Pain In Your Eye
Often, eye pain that feels like something is in the eye actually is caused by irritation or inflammation of the front surface of the eye, particularly the cornea.
Common causes of pain emanating from the front surface of the eye or inside the eye include:
Corneal foreign body. Not surprisingly, what often causes a foreign body sensation in the eye is an actual foreign body. Common foreign bodies that can adhere to and become embedded in the surface of the cornea include metal shavings, inorganic grit (sand, tiny stone particles), sawdust and other organic material.
The discomfort from a corneal foreign body can range from mild to severe, and typically it is most bothersome when you’re blinking (since the eyelid often is rubbing across it during blinks). Blurred vision and sensitivity to light also are common.
A corneal foreign body requires urgent attention from an eye doctor, because material embedded in the cornea can quickly cause a serious eye infection.
Most corneal foreign bodies can be removed easily in the doctor’s office with the proper tools. Antibacterial eye drops may be prescribed to prevent infection while the cornea heals.
Corneal abrasion. This is a scratched cornea. Although most corneal abrasions are not serious, they can be very uncomfortable and cause light sensitivity and watery eyes.
Many superficial corneal scratches heal on their own within 24 hours. But deeper abrasions can lead to a serious eye infection and even a corneal ulcer if left untreated.
Because it’s often impossible to tell if eye pain is due to a minor scratch, a deep abrasion or a corneal foreign body, it’s a good idea to see an eye doctor for any sharp discomfort of the eye that does not resolve very quickly, to determine the underlying cause.
Dry eyes. Another very common cause of eye discomfort is dry eyes. Usually dry eye discomfort begins more slowly and gradually than eye pain from a corneal foreign body or abrasion. Sometimes dry eyes can lead to a corneal abrasion, because there are not enough tears on the surface of the eye to keep the cornea moist and slippery.
If using lubricating eye drops significantly improves comfort, the cause of the pain is probably dry eyes. In most cases, dry eye does not require urgent attention; but your eye doctor can perform tests to determine the severity of the dryness and recommend the most effective treatment.
Other (less common) causes of anterior eye pain, or pain “in” the eye, include:
- Conjunctivitis (pink eye)
- Eye infections (including fungal eye infections and Acanthamoeba keratitis)
- Iritis (anterior uveitis), which is inflammation of the iris
- Contact lens discomfort
A very serious cause of pain in the eye is a condition called endophthalmitis (en-dahf-thal-MITE-is), which is inflammation of the interior of the eye that most often is caused by a bacterial infection. It also can occur as a rare complication of cataract surgery.
Endophthalmitis, in addition to causing eye pain, causes redness, swollen eyelids and decreased vision. If you have these symptoms after cataract surgery or other eye surgery, see your eye doctor immediately.
Pain Behind Your Eye
Common causes of pain behind the eyes are migraine headaches and sinus infections.
In the case of a migraine headache, the pain almost always is behind only one eye and often is accompanied by pain elsewhere on the same side of the head.
Pain behind the eye from a sinus infection usually is less severe than pain from a migraine, and both eyes may be affected.
Though pain behind the eyes from these causes typically is not an emergency, if you have chronic or recurring pain of this type, see your eye doctor or general physician for treatment and to see what can be done to prevent future episodes.
