Bulging or protruding of one or both eyes is called proptosis or exophthalmos. Exophthalmos is usually used when describing bulging eyes caused by Graves disease, a disorder causing overactivity of the thyroid gland (hyperthyroidism). Bulging eyes are not the same as prominent eyes. Some disorders that may change the appearance of the face and eyes but that do not cause true eye bulging include Cushing disease and severe obesity.
Bulging sometimes causes other symptoms. The eyes may be dry and irritated (which causes watering) because the bulging may prevent the eyelids from closing properly. Also, people may blink less often or may appear to stare. Depending on the cause of bulging, people may have other symptoms such as double vision or difficulty focusing on objects. If bulging is prolonged, the optic nerve is stretched, which may impair vision. Vision may also be impaired if the disorder causing bulging also presses on the optic nerve.
Causes
The most common cause in adults is Graves disease, which causes swelling of tissue behind and around the eye, pushing the eyeball forward. In children, the most common cause is infection.
Other causes are uncommon. They include tumors, bleeding, infections (in adults), and, rarely, inflammation of structures within the orbit without infection (called orbital pseudotumor). Glaucoma that is present from birth (primary infantile glaucoma) can cause the eyes to enlarge, which may seem to look similar to eyes that are pushed forward.
Some Causes and Features of Bulging Eyes
Cause |
Common Features* |
Tests |
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Eye symptoms: Pain, watering, dryness, irritation, sensitivity to light, double vision, and loss of vision Usually affecting both eyes General symptoms: Palpitations, anxiety, increased appetite, weight loss, diarrhea, inability to tolerate heat, increased sweating, and insomnia |
Blood tests to evaluate thyroid gland function Sometimes CT or MRI |
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Orbital cellulitis (infection of the tissue within the eye socket, or orbit) |
Affecting only one eye Eye redness, pain deep within the eye, pain when moving the eye, and aches in and around the eye Red and swollen eyelids Inability to fully move the eye in all directions Impaired vision or loss of vision Fever Sometimes preceded by symptoms of sinusitis |
CT or MRI |
|
A mass in the eye socket such as a tumor (cancerous or not) or blood vessel malformation |
Loss of or a decrease in vision and pain in one eye Sometimes double vision or headache |
MRI or CT |
|
Retrobulbar hemorrhage (bleeding in the eye socket) |
Usually affecting only one eye Symptoms that begin suddenly Loss of vision, double vision, and eye pain In people who have recently had eye surgery or an eye injury or who have a bleeding disorder |
CT or treatment done immediately |
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* Features include symptoms and the results of the doctor's examination. Features mentioned are typical but not always present. |
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CT = computed tomography; MRI = magnetic resonance imaging. |
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Evaluation
The following information can help people decide when a doctor's evaluation is needed and help them know what to expect during the evaluation.
Warning signs
When to see a doctor
What the doctor does
Doctors first ask questions about the person's symptoms and medical history. Doctors then do a physical examination. What they find during the history and physical examination often suggests a cause for eye bulging and the tests that may need to be done (see table Some Causes and Features of Bulging Eyes).
Doctors ask
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How long the bulging has been present
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Whether both eyes are bulging
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Whether bulging seems to be getting worse
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Whether the person has other eye symptoms, such as dryness, increased tear formation, double vision, loss of vision, irritation, or pain
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Whether the person has symptoms of hyperthyroidism, such as inability to tolerate heat, increased sweating, involuntary shaking movements (tremors), anxiety, increased appetite, diarrhea, palpitations, and weight loss
Bulging that has developed rapidly (over a few days) suggests different causes than bulging that has developed over years. Rapid bulging in only one eye suggests bleeding in the eye socket (orbit), which can occur after surgery or injury, or infection or inflammation of the eye socket. Bulging that develops slowly suggests Graves disease (when it affects both eyes) or a tumor in the eye socket (when it affects one eye).
The physical examination is focused on the eyes. Doctors examine the eyes for redness, sores, and irritation using a slit lamp (an instrument that enables a doctor to examine the eye under high magnification). They check whether the eyelids move as fast as the eyeball when the person looks down and check for staring. Slow eyelids and staring could indicate Graves disease.
Doctors may also check for other signs that could indicate hyperthyroidism, such as increased heart rate or blood pressure, tremors, and a swollen or tender thyroid gland in the neck.
Testing
Treatment
When bulging leads to severe dry eyes, lubrication with artificial tears is needed to protect the cornea (the clear layer in front of the iris and pupil). Sometimes if lubrication is not sufficient, surgery to provide better coverage of the eye surface or to reduce bulging may be needed.
Other treatments depend on the cause of bulging. For example, antibiotics are given for infections. Bulging due to Graves disease is not affected by treatment of the thyroid condition but may lessen over time. Corticosteroids (for example, prednisone) may help control swelling due to Graves disease or orbital pseudotumor. Tumors must be surgically removed.
