Bulging eyes in adults (mata terkeluar): thyroid disease and the other causes, and what the sources say about phones

One eye looks bigger, or both look wider than they used to. In Malay it is "mata terkeluar", and the same three worries come up: is it thyroid, will it go back, and is it my phone? The short version is that thyroid disease is the commonest cause in adults, but it is not the only one, and a few causes cannot wait. This piece starts with the ones that cannot wait, then goes through the rest.

Is bulging eyes always a thyroid problem?

No. Thyroid eye disease is the commonest cause in adults, but it is not the only one. StatPearls, the NCBI's clinical reference, says exactly that: in adults the most common cause of bulging in one or both eyes is thyroid-associated eye disease, and clinicians need to know the other causes because they are easily missed in people whose thyroid tests are abnormal. The same chapter says that when only one eye bulges, under a third of patients have an overactive thyroid.

The medical name for a forward-pushed eye is proptosis, also called exophthalmos. It means the contents of the eye socket, the bony orbit, have grown or swelled, and the only way out is forwards. The National Eye Institute describes thyroid eye disease as swelling around the eyes, caused by Graves' disease, in which the immune system attacks the thyroid and sometimes the tissues around the eyes as well. I have written about that in full in the signs and treatment of thyroid eye disease, so this page does not repeat it. It looks at everything else that can push an eye forward.

When is a bulging eye an emergency?

Go to a hospital or an eye doctor the same day if the eye has moved forward quickly, or if the bulge comes with pain, double vision, blurred vision, fever, or a hot red eye. Speed matters. StatPearls notes that rapid onset suggests inflammatory disease, a malignant tumour or a carotid-cavernous fistula (an abnormal blood vessel connection behind the eye), while gradual onset points to slower, more benign causes. It adds that pain commonly means infection.

The infection to think of first is orbital cellulitis, infection of the tissue behind the eyelid. A review in the Community Eye Health Journal lists proptosis, red swollen lids, limited eye movement, pain and reduced vision among its signs, and calls it life-threatening because infection can spread into the brain. Treatment is intravenous antibiotics started at once, so it is a hospital emergency, not an appointment for next week. My article on orbital cellulitis and abscess explains the surgical side.

Vision is the other reason not to wait. The National Eye Institute says that in rare cases swelling around the eyes presses on the optic nerve, the cable from the eye to the brain, and causes vision loss. Any bulge with dimming vision or new double vision needs an eye doctor quickly. You do not need to know the cause before you go.

What else, besides thyroid, can push an eye out?

Four broad mechanisms, according to StatPearls. Inflammation spreading into the orbit, such as orbital cellulitis, sarcoidosis, granulomatosis with polyangiitis or IgG4-related disease. A new growth in the orbit, benign or malignant. Blocked or abnormal venous drainage from the orbit. And foreign matter or trauma forcing something into the socket. Thyroid eye disease belongs to the first group, which is why it is one of several inflammatory causes rather than a category of its own.

A growth is the cause that frightens people most, so the honest detail matters. The StatPearls list of orbital growths runs from capillary haemangioma to lymphoma, mucocele (a fluid-filled sac), pseudotumour (inflammation that behaves like a mass) and cancer that has spread from elsewhere. Many are not cancer. A Malaysian case series in the Malaysian Family Physician describes a 53-year-old woman with gradual, painless bulging of one eye, normal thyroid tests and a cavernous haemangioma, a benign cluster of blood vessels, on an MRI scan. She was managed conservatively with six-monthly follow-up.

Blood vessels can do it too. StatPearls says an eye that bulges only briefly when you strain, the Valsalva manoeuvre, may point to orbital varices, which are swollen veins in the socket. Trauma can do it, and orbital fracture after a knock to the eye covers that. I co-presented a conference study on a question that sits right here: whether orbital lymphoma can be reliably told from inflammatory disease before a biopsy. I will not quote a result from a presentation, but the question shows why some bulging eyes need a small tissue sample and not only a scan.

Does using a phone make the eyes bulge?

The sources used for this page show no evidence that it does. It is a common question, so it deserves a straight answer. None of the sources used for this page lists phone or screen use among the causes. The mechanisms StatPearls gives are inflammation, growth, venous drainage and foreign matter or trauma, and the Malaysian case series groups causes as vascular, inflammatory, traumatic, autoimmune, iatrogenic (caused by medical treatment), neoplastic (a growth), congenital and endocrine. Screens are not on either list.

That is a statement about what the sources say, and I will not invent a mechanism to fill the gap. The practical point is the one that matters. If an eye has changed in size or position, blaming the phone can delay the assessment that finds the real cause. Reducing screen time may be good for other reasons, but it is not a treatment for a bulging eye.

Could my eyes only look bulging when they are not?

Yes, this happens. Pseudoproptosis is the appearance of bulging without a mass or swelling pushing the eye forward, and the Malaysian case series names high myopia (very short-sightedness) as one cause. It describes a 54-year-old man with painless bulging in both eyes for 5 years, normal thyroid blood tests and no mass on an MRI scan, who was diagnosed with pseudoproptosis from high myopia and followed up yearly.

The eyelid can also create the illusion. EyeWiki, from the American Academy of Ophthalmology, describes upper eyelid retraction as an abnormally high resting position of the lid. It shows white between the lid and the coloured part of the eye, which gives a stare with an illusion of bulging. Thyroid eye disease is the most common cause of that too, but retraction can also come from other things, including some eyelid or eye operations. Eyelid retraction after surgery covers one of them.

The difference between a real and an apparent bulge is measured, not guessed. An exophthalmometer, a small ruler-like instrument, measures how far the front of the eye sits from the bony rim of the socket. The Malaysian case series gives the normal reading as under 21 mm, or a difference of less than 2 mm between the two eyes.

What happens at an assessment, and can it be reversed?

An eye doctor examines the eyes and lids, measures the bulge, checks vision and eye movements, and usually arranges blood tests and often a scan. The National Eye Institute says thyroid eye disease is diagnosed by an eye exam, with blood tests to check the thyroid if it is suspected. StatPearls lists the wider workup: blood counts, thyroid tests, inflammatory markers, and CT or MRI of the orbit, with a tissue biopsy sometimes needed when the picture is unclear.

Whether it can be reversed depends on the cause, and every source used here says the same first step: treat the underlying cause. For thyroid eye disease, the National Eye Institute says it is often mild, symptoms usually last 1 to 2 years and often go away on their own, and treatment ranges from lubricating drops to steroids to surgery. Orbital decompression, an operation that makes the eye socket bigger, is used when vision is threatened, and it can help the eye move back. I describe it in what orbital decompression does. For a growth or an infection, the treatment is different again, which is the reason for a proper diagnosis first.

In Malaysia the usual route is your family doctor or a klinik kesihatan, who can write a surat rujukan (referral letter) to an eye clinic, and to an endocrinologist if the thyroid is involved. If only one eye looks different, why one eye looks different explains why that alone is not reassuring, and orbital conditions explained shows what else lives in the socket. For a wider view of how the eye area changes, see the guide to what makes eyes look tired, and the rest of this cluster sits under orbit and thyroid conditions.