{"id":1822,"date":"2026-10-20T08:52:16","date_gmt":"2026-10-20T08:52:16","guid":{"rendered":"https:\/\/laseristanbulclinic.com\/eye-glossary\/exophthalmos\/"},"modified":"2026-10-20T12:56:44","modified_gmt":"2026-10-20T12:56:44","slug":"exophthalmos","status":"publish","type":"page","link":"https:\/\/laseristanbulclinic.com\/en\/eye-glossary\/exophthalmos\/","title":{"rendered":"Exophthalmos: Bulging Eyes, Causes, Symptoms and Treatment"},"content":{"rendered":"\n
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  1. Home<\/a><\/li>
  2. Knowledge centre<\/a><\/li>
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  4. Exophthalmos: Bulging Eyes, Causes, Symptoms and Treatment<\/span><\/li><\/ol><\/div>\t\t\t

    Exophthalmos: Bulging Eyes, Causes, Symptoms and Treatment<\/h1>\n\t\t\t\t\t\t

    Medically reviewed by {{surgeon}}<\/span><\/strong>, {{surgeon’s title and specialty}}<\/span>, on {{review date}}<\/span>. Last updated {{date}}<\/span>.<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t

    \"Illustration<\/figure><\/div>\n\t\t\t<\/div><\/div>\n<\/section>\n\n\n\n\n
    \n\t\t<\/svg>Definition<\/span>\n\t\t\t

    Exophthalmos<\/strong> (noun; also called proptosis)<\/em>: exophthalmos is the forward bulging of one or both eyes out of the eye socket (the orbit). It happens when something inside the orbit, such as swollen muscle and fat, a growth, an infection or a blood vessel problem, takes up more room and pushes the eye forward. In adults the most common cause is thyroid eye disease, usually linked to Graves’ disease, but sudden or one-sided bulging with pain, fever or lost vision is an emergency.<\/p>\n\t\t<\/div><\/div><\/div><\/div><\/section>\n\n\n\n\n

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    Exophthalmos: key facts<\/h2><\/div>\n\t\t\t\t\t<\/div>\n\t\t\t
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    <\/svg>Other names<\/span><\/dt>
    Proptosis, bulging eyes, protruding eyes. “Exophthalmos” comes from the Greek for “bulging eyes”<\/dd><\/dl><\/div>\n\t\t\t\t
    <\/svg>What it is<\/span><\/dt>
    A sign, not a disease in itself: the eye is pushed forward because the contents of the bony orbit have increased<\/dd><\/dl><\/div>\n\t\t\t\t
    <\/svg>One eye or both?<\/span><\/dt>
    Both eyes usually points to a general cause such as thyroid eye disease; one eye more often points to a local cause such as a tumour, infection or blood vessel problem<\/dd><\/dl><\/div>\n\t\t\t\t
    <\/svg>Most common cause in adults<\/span><\/dt>
    Thyroid eye disease (Graves’ orbitopathy)<\/dd><\/dl><\/div>\n\t\t\t\t
    <\/svg>How it is measured<\/span><\/dt>
    With a Hertel exophthalmometer (a small handheld device that measures how far the front of the eye sits in front of the orbital rim), plus CT or MRI scans<\/dd><\/dl><\/div>\n\t\t\t\t
    <\/svg>Urgent warning signs<\/span><\/dt>
    Sudden bulging, pain, fever, double vision, a drop in vision, or an eye that cannot close<\/dd><\/dl><\/div>\n\t\t\t\t
    <\/svg>Who treats it<\/span><\/dt>
    An ophthalmologist (often an oculoplastic or orbital specialist) together with an endocrinologist when the thyroid is involved; at Laser Istanbul Clinic, eyelid and oculoplastic assessment is with Prof. Dr. Ahmet Sat\u0131c\u0131<\/dd><\/dl><\/div>\n\t\t\t<\/div>\n\t\t<\/div><\/div><\/div><\/section>\n\n\n\n\n
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    What is exophthalmos?<\/h2><\/div><\/div>

    Exophthalmos is a medical term for eyes that protrude forward out of the orbit. The StatPearls medical reference describes it as the protrusion of one or both eyes anteriorly out of the orbit, caused by an increase in the contents of the bony orbit. The eye socket is a rigid cone of bone, so if its contents (the eye itself, the eye muscles, fat, nerves and blood vessels) swell or something new grows inside it, the only way out is forward.<\/p><\/div>

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    Exophthalmos or proptosis: what is the difference?<\/h3>

    In everyday medical use the two words mean the same thing. “Proptosis” is the broader, more modern term and is used for forward displacement of the eye from any cause. “Exophthalmos” is often kept for bulging caused by thyroid eye disease, but the terms are used interchangeably, and both are correct for this page.<\/p><\/div><\/div>

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    Is it the same as having "big eyes" or a "staring look"?<\/h3>

    Not always. A person can look as though their eyes bulge when the eyelids are simply sitting too high (eyelid retraction), exposing more of the white of the eye. This is common in thyroid eye disease, where eyelid retraction occurs in up to about 90% of patients, and it can exist with or without true forward displacement of the eye. Doctors call a bulging look without real forward displacement “pseudoproptosis”. An examination and measurement tell the two apart.<\/p><\/div><\/div>

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    What is a normal eye position?<\/h3>

    There is no single normal number. Normal exophthalmometer readings vary with age, sex and ethnic background; a 2022 study of 1,000 North Indian adults, for example, found an average reading of 14.9 mm with a range from 8 to 22 mm, while a 2026 study of a Japanese population found an average of 15.6 mm. Because of this, doctors judge a reading against the person’s own background, compare the two eyes, and look at whether the position has changed over time. A change, or an eye that looks different from the other, matters more than one reading on its own.<\/p><\/div><\/div><\/div>\t<\/div><\/div><\/div>\n<\/section>\n\n\n\n\n

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    What causes exophthalmos?<\/h2>\n\t\t\t

    Causes fall into a few groups. Thyroid disease is by far the most common in adults.<\/p>\n\t\t\t

    Cause<\/th>How it pushes the eye forward<\/th>Usually affects<\/th><\/tr><\/thead>
    Thyroid eye disease<\/strong> (Graves’ orbitopathy)<\/th>The immune system inflames and swells the eye muscles, fat and connective tissue in the orbit<\/td>Both eyes, often unevenly; one eye sometimes<\/td><\/tr>
    Orbital cellulitis<\/strong><\/th>A bacterial infection, often spreading from the sinuses, swells the tissue behind the eyelid<\/td>Usually one eye; emergency<\/td><\/tr>
    Orbital inflammation (non-thyroid)<\/strong><\/th>Inflammation of orbital tissue without infection, sometimes related to other immune conditions<\/td>One or both eyes<\/td><\/tr>
    Tumours and growths<\/strong><\/th>A benign or malignant growth in the orbit takes up space; examples include a cavernous haemangioma (a benign blood-vessel tumour)<\/td>Usually one eye, gradually<\/td><\/tr>
    Blood vessel problems<\/strong><\/th>Abnormal vessels or a bleed behind the eye increase the volume or pressure in the orbit<\/td>Usually one eye<\/td><\/tr>
    Injury<\/strong><\/th>Bleeding or swelling inside the orbit after trauma<\/td>One eye<\/td><\/tr>
    Other<\/strong><\/th>Inherited skull and orbit conditions, and in children some tumours and cancers, including leukaemia<\/td>Varies<\/td><\/tr><\/tbody><\/table><\/div><\/div>\n\t\t\t
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    Thyroid eye disease: the most common cause<\/h3>

    Thyroid eye disease (TED, also called Graves’ ophthalmopathy or Graves’ orbitopathy) is an autoimmune condition. The immune system attacks tissue around the eyes, the orbital fibroblasts become active, and the eye muscles and orbital fat swell. Several points are worth knowing:<\/p>\n