Bulging of one or both eyes, making them look abnormally prominent

  • More common in females
  • Age, genetics, and lifestyle are not significant factors

If the tissue in the eye socket swells, the eyeball can protrude, causing a staring appearance known as exophthalmos (also sometimes called proptosis). The condition usually affects both eyes and is more common in women. It is often linked with an overactive thyroid gland (see Hyperthyroidism). Less commonly, the cause may be bleeding or infection behind the eye, a tumour, or a cyst. In these cases, usually only one eye is affected.

Severe exophthalmos can result in blurred vision because of pressure on the eye. Abnormal eye movement may lead to a change in the position of the eye, which can result in double vision. Exophthalmos may keep the eyelids from closing properly, causing the front of the eye to dry out, increasing the risk of damage to the cornea.

What is the treatment?

Exophthalmos may be corrected by dealing with the underlying cause, such as by treating a bacterial infection with antibiotics. However, if the exophthalmos is due to hyperthyroidism, it often remains after the underlying condition has been treated.

If exophthalmos persists, you may need surgery to make more room for the eye by removing part of the socket.


The staring appearance of this eye is due to swelling of tissues in the eye socket, making the eye bulge forwards (exophthalmos).

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.

Back to top