What causes eye pain?

Eye pain can describe discomfort in, on, behind or around the eye. You can experience right eye pain, left eye pain or pain relating to both eyes.

In some cases, like after an eye injury, the cause of eye pain is obvious. Other times, it's hard to know why your eyes hurt.

The severity of eye pain does not necessarily indicate how serious the underlying cause of the discomfort is. A somewhat minor problem, like a corneal abrasion, can be very painful. On the other hand, many serious eye conditions — such as cataracts, macular degeneration and retinal detachment — don't cause any eye pain at all.

Different sensations and symptoms can come with a painful eye. Your eye doctor can use these factors to diagnose the cause of your pain and prescribe the best treatment.

Eye pain symptoms can include one or more of the following:

A sharp, stabbing sensation

A dull ache

Burning or stinging eyes

The feeling that something is stuck in your eye

You may also notice: 

Blurry vision

Eye redness 

Sensitivity to light

Causes of eye pain on the surface of the eye
Several problems can make your eye hurt along the front surface:

Corneal foreign body
A feeling that something is stuck in your eye can be deceiving because it doesn't always mean something is stuck in your eye. But when something is in your eye, doctors refer to it as a "foreign body."

Foreign bodies can get lodged in the cornea, the clear front surface of the eye, and cause pain and other irritation. Examples include:

Dirt

Sand

Tiny stone particles

Metal shavings

Sawdust

Other small particles and debris

Discomfort from one of these foreign objects can range from mild to severe. It's usually most bothersome when you blink. Blurred vision and light sensitivity are also common.

Particles on the surface of the eye can turn into serious eye infections, so it's important to wear protective eyewear if you work in a hazardous environment, and to visit an eye doctor if you experience eye pain and irritation after getting something in your eye.

Fortunately, eye doctors can easily remove most corneal foreign bodies.

Corneal abrasion
Corneal abrasion is another way of saying your cornea is scratched. Most corneal abrasions aren't serious, but they can be very uncomfortable and cause light sensitivity and watery eyes.

Many mild corneal scratches heal on their own within 24 hours. 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, deep abrasion or foreign body, it's a good idea to see an eye doctor for any sharp eye discomfort that doesn't go away quickly.

Dry eyes
Dry eye discomfort usually develops more gradually than pain from a corneal foreign body or abrasion. Sometimes, dry eyes can lead to a corneal abrasion, because there aren't 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 immediate medical attention, but an eye doctor can perform tests to determine the degree of dryness and recommend the best treatment.

Other causes of eye pain
Less common causes of pain on or "in" the eye include:

Pink eye

Eye infections (including fungal eye infections and Acanthamoeba keratitis)

Iritis

Contact lens discomfort

Endophthalmitis
A very serious cause of pain in the eye is a condition called endophthalmitis, an inflammation of the inside of the eye. It is usually caused by a bacterial infection from a penetrating eye injury. It can also be a rare complication of cataract surgery or other eye surgery.

In addition to causing eye pain, endophthalmitis causes redness, swollen eyelids, blurry vision and difficulty seeing. If you notice these symptoms after eye surgery, see an eye doctor immediately.

Causes of eye pain behind the eyes
Migraine headaches and sinus infections are the two most common causes of pain behind the eye.

Migraine pain is almost always behind one eye and often accompanied by pain somewhere else on the same side of the head.

When pain behind the eye is caused by a sinus infection, it's usually less severe than the pain from a migraine. Both eyes can be affected by sinus problems.

Though pain behind the eyes from a migraine or sinus infection isn't usually an emergency, you should see an eye doctor or general physician if you have new or recurring pain.

Causes of eye pain around the eyes
Pain around the eyes is most commonly caused by:

Stye

Blepharitis

Digital eye strain

One of the most common causes of pain around the eyes is an eyelid stye. 

A stye doesn't require urgent attention from an eye doctor. It can usually be successfully treated at home by applying a warm compress to the affected eyelid several times a day for a few days.

Blepharitis is another common problem that can cause swollen eyelids and discomfort around the eyes.

Digital eye strain, sometimes called computer vision syndrome, can also cause pain around the eyes. This is not an urgent problem, and there are simple steps you can take to relieve computer eye strain.

A rare and very serious cause of pain around the eyes is a condition called optic neuritis, which can cause permanent vision loss. Accompanying symptoms are usually decreased visual sharpness and reduced color vision.

Pain from optic neuritis is usually worse when you move your eyes. It requires immediate medical attention, which may include a referral to a neuro-ophthalmologist.

Eye pain treatment
If you have eye pain, consider it a medical emergency. Make it a priority to see an eye doctor who can diagnose the cause of your pain and prescribe the best treatment to limit any potential damage.

In particular, see your eye doctor immediately if you have a painful eye and:

The pain occurred immediately after grinding metal, sawing wood or doing other activities that could allow debris to enter, scratch or irritate your eye (especially if you weren't wearing safety glasses or protective eyewear).

The pain is due to an eye injury.

The pain is severe and is accompanied by blurred vision and/or sensitivity to light.

You had a recent eye surgery, such as LASIK or cataract surgery.

Your eyes are red and you see discharge coming from them.

The pain is severe, comes on suddenly, and you have a history of glaucoma. This could be a sign of angle-closure glaucoma, which can cause rapid vision loss and is a medical emergency.

When it comes to eye pain, don't take chances. See an eye doctor as soon as possible to determine the exact cause of the pain and make sure you receive the best treatment.