Patients who develop thyroid eye disease may report a range of different symptoms, depending on the tissues that are involved and the extent of inflammation and swelling. The most commonly reported symptom associated with thyroid eye disease is a change in appearance characterized by the development of a constant stare. This change usually reflects the combined effects of proptosis and increased retraction of the upper eyelids due to untreated thyrotoxicosis. Some patients may note this change in appearance on their own, while others may have had it pointed out to them by observers. Other commonly reported symptoms include a sensation of pressure building up in the eye sockets along with increased redness and watering of the eyes. Some patients may report increased sensitivity to bright light, a symptom called photosensitivity. Other may report irritation that feels like a piece of sand or grit may be stuck on the surface of an eye, a symptom called a foreign body sensation. Patients with mild thyroid eye disease may report transient blurring of vision related to increased production of tears or excessive drying of the cornea.
Patients with severe thyroid eye disease may report blurring of vision due to compression of the optic nerves. The optic nerves function to transmit signals from the retina of each eyeball to the vision center of the brain. In early stages, blurring of vision due to compression of the optic nerves may be associated with changes in the perception of the brightness of certain colors. As blurring of vision progresses, it may be associated with the appearance of gaps in fields of vision. Patients with severe thyroid eye disease may also report problems with double vision due to entrapment of the extraocular muscles that control the movement of the eyeballs. In early stages, double vision may only occur when a patient’s eyes move to look in a certain direction. It may also occur when a patient becomes fatigued after a long period of exertion. With progression, double vision may become sustained. Entrapment of the extraocular muscles may lead to significant changes the alignment of the eyeballs and pupils that may be visible to observers.