What can cause one bulging eye?

A bulging eye: Needs to be evaluated by an ophthalmologist or a pediatric ophthalmologist, if in a child, asap to find out what is causing increased pressure on or in the globe (eyeball). Start with your primary care doctor today/tomorrow for a medical evaluation & to get a referral straight away.

Many: Some people have asymmetry that is natural. A new bulging eye is not natural and should be medically evaluated. The most common cause of a bulging eye is thyroid disease.

Possible tumpr: A single bulging eye could be thyroid disease or a tumor behind the eye if this is a new problem. See your ophthalmologist soon.

Thyroid, others: In the 19 year old age group, thyroid malfunction is the most likely diagnosis. Less common are tumors behind the eye, some primary and some metastatic. If the bulging is accompanied by pain, especially on eye motion it could be infectionl this always requires evaluation and you should see a neuro-ophthalmologist or oculoplastic surgeon (not an optometrist).

Bulging eye: The most common cause of unilateral proptosis in an adult is thyroid eye disease.