There are many causes of exophthalmos (bulging eyes), also known as proptosis, but the most common cause is Grave’s disease – an autoimmune disease which affects the thyroid gland, causing the overproduction of thyroid hormones, leading to abnormalities in various organs – including the eyes.
Exophthalmos is the main symptom of Grave’s disease. It occurs as a result of excess hormones accumulating in the muscles and fatty tissues behind the eyes. It causes swelling in the eye sockets, which leads to protruding eyes. The condition occurs gradually until it becomes clearly noticeable. In some cases, patients may also experience double vision and abnormal eye movement.