Many factors — such as an infection, a preexisting condition, or trauma — can cause a swollen eyeball. This often requires medical attention.

A swollen eyeball is different from swelling around the eye or a swollen eyelid. Instead, a swollen eyeball involves the eye itself rather than the surrounding areas.

This article will examine some causes of a swollen eyeball. It will also look at potential treatments and when a person should seek medical advice.

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If a person has a swollen eyeball, the white part of their eye may bulge out and look jelly-like.

They may also experience symptoms such as:

  • red, itchy eyes
  • watery discharge from one or both eyes
  • swollen eyelids
  • flushed, puffy skin around the eyes
  • blurry vision
  • dark, floating spots in their vision
  • eye pain
  • difficulty moving the eyes
  • sensitivity to light

Several factors can cause a person’s eyeball to become swollen, including:

1. Injury

A person may sustain an injury to their eye that results in a swollen eyeball. These injuries may include:

  • impact to the eye
  • exposure to chemicals
  • foreign bodies in the eye
  • lacerations or abrasions of the eyeball

Treatment varies depending on the type of injury.

For example, treatment for chemical exposure may include irrigation and, depending on the chemical, eye drops. A person can treat an impact to the eye using an ice pack. Lacerations or abrasions may require an eye patch to allow the eye to rest and heal.

2. Conjunctivitis

Also known as “pink eye,” conjunctivitis is a common cause of a swollen eyeball.

A viral or bacterial infection of the conjunctiva causes conjunctivitis. The conjunctiva is the sensitive membrane that covers the eyeball and inner surface of the eye.

Conjunctivitis usually resolves itself within 7–10 days but may need medical intervention.

Some symptoms of conjunctivitis include:

  • swelling of the eye
  • red or pink eyes
  • watery discharge
  • sensitivity to light

Treatment may include antibiotics, if the infection is bacterial, and cold compresses. People should also avoid rubbing their eyes, as this can make conjunctivitis worse.

Additionally, people should ensure that they do not share washcloths, towels, or other linens with anyone, as conjunctivitis can be contagious. People should also dispose of the makeup they used while experiencing conjunctivitis, and they should not wear contact lenses.

3. Allergic conjunctivitis

A person may have an allergic response to foreign particles in their eyes, such as pollen, dust, or pet dander. If the person is overly sensitive to these allergens, their body may release histamines in the eyes, causing inflammation to the conjunctiva.

Some symptoms of allergic conjunctivitis include:

  • red eyes
  • swollen eyelids
  • itchy eyes
  • swollen eye surface
  • watery discharge

Treatment for allergic conjunctivitis may include:

  • cold compresses
  • eye drops
  • antihistamines

Also, people should avoid rubbing the eye area if they have allergies, as this can make symptoms worse. They should also avoid wearing contact lenses if they have allergic conjunctivitis.

4. Chemosis

Chemosis is another cause of inflammation of the conjunctiva. A person may be unable to close their eye due to the swelling. Conjunctivitis can cause a person to develop chemosis, though this is rare.

Chemosis can also be a complication of undergoing eye surgery, or it may develop if a person rubs their eyes too much.

Some symptoms of chemosis include:

  • severe swelling of the eyeball
  • itchiness
  • blurry vision
  • tearing up

Treatment options will depend on the cause of the chemosis but may include:

  • eye drops
  • antihistamines
  • antibiotics

The key to treating chemosis is to manage the swelling while treating the underlying cause.

5. Scleritis

Scleritis refers to rare, severe inflammation of the sclera, which is the white part of the eyeball. This is a medical emergency,

Some symptoms of scleritis include:

  • redness
  • swelling
  • an aching pain
  • blurry vision
  • pain while moving the eye

Scleritis treatment may involve a range of oral medications to reduce inflammation and suppress the body’s immune system.

Doctors usually refer people with scleritis to see an eye specialist urgently.

6. Subconjunctival hemorrhage

Subconjunctival hemorrhage occurs when blood leaks from one or more breaks in a blood vessel between the sclera and the conjunctiva.

Some symptoms of subconjunctival hemorrhage include red spots of blood and a scratchy sensation on the eye’s surface.

Despite the appearance, subconjunctival hemorrhage is usually harmless and causes no change in vision, no pain, and no discharge from the eye.

Subconjunctival hemorrhage should heal without treatment. If a person experiences subconjunctival hemorrhages frequently, however, they may require further testing to determine the cause.

7. Uveitis

Uveitis is a term used to describe a group of inflammatory conditions that uveitis“>all produce swelling and destroy eye tissue. These usually affect the part of the eye known as the uvea but may also affect other parts of the eyeball.

Infections, diseases, and injuries occurring in the eye may cause uveitis. An inflammatory condition that affects other parts of the body could also result in uveitis.

Some symptoms of uveitis include:

  • eye pain
  • blurry vision
  • floaters
  • sensitivity to light
  • vision loss

Uveitis treatments may include:

  • eye drops
  • injections
  • oral medications
  • surgery

Medications that can treat uveitis include nonsteroidal anti-inflammatory drugs and immunosuppressive medications. In some cases, a doctor may also implant time-release capsules in the eyes.

A doctor may ask questions to determine the cause of a swollen eyeball. For example, they may ask the person about:

  • when the swelling began
  • the severity of the swelling
  • whether or not the swelling has happened before
  • what they were doing when the swelling started
  • whether or not anything makes the swelling worsen or improve
  • any other symptoms they may be experiencing

The doctor may order an eye test to determine the impact on the person’s vision. They may also conduct laboratory tests to investigate whether the cause could be an infection or an autoimmune condition.

Swollen eyeballs do not always require medical attention. For example, if a person frequently experiences conjunctivitis, they may be able to treat it with home remedies.

For instance, a person can make cold compresses and apply them to their closed eyes. For this, they should use clean washcloths soaked in boiled, cooled water that has been in the refrigerator.

If the swelling results from an allergy, people should try to avoid the cause of the allergy as much as possible.

If the swelling results from an injury, a person could try using an ice pack at home before seeking medical attention. To do this, they should wrap an ice pack in a towel or similar to prevent further damage to the eye area.

A person should contact a doctor if their symptoms get worse or do not improve.

If a person is experiencing other symptoms alongside a swollen eyeball — such as eye pain, vision loss, or an inability to close their eyes — they should immediately contact a doctor.

A person should also ask for a doctor’s advice if they have an underlying condition such as diabetes or cancer, as these could cause complications.

A swollen eyeball may not cause concern. Sometimes, however, it could indicate an underlying condition.

The best treatment for a swollen eyeball will depend on the cause and its severity. Without treatment, a severe condition causing a swollen eyeball could cause permanent damage.

A person should contact a doctor as soon as possible if they experience severe symptoms with a swollen eyeball.