Thyroid eye disease symptoms can develop independently of thyroid hormone levels, making them a challenging aspect of autoimmune thyroid conditions that is often misunderstood. Thyroid eye disease (TED) — also called Graves' ophthalmopathy or Graves' orbitopathy — is an autoimmune condition in which the immune system attacks the tissues around the eyes, causing inflammation, swelling, and structural changes in the orbit 1.
It occurs most commonly in people with Graves' disease (the most common cause of hyperthyroidism), but can also occur in those with Hashimoto's thyroiditis or even in people who are euthyroid (with normal thyroid function). TED is more common in women, though men tend to have more severe disease 2.
This page describes the full range of thyroid eye disease symptoms, how the condition progresses, and when to seek specialist evaluation — which is important because early treatment can prevent permanent vision changes. For related thyroid topics, see our guides to Graves' disease symptoms and treatment and the broader hormones and thyroid hub.
What Causes Thyroid Eye Disease?
Thyroid eye disease results from autoimmune activity involving the TSH receptor (thyroid-stimulating hormone receptor), which is expressed not only in the thyroid gland but also in orbital fibroblasts — connective tissue cells in the tissues around and behind the eyes 1. When autoantibodies bind these orbital receptors, they trigger a cascade of inflammation and glycosaminoglycan accumulation in the orbital fat and extraocular muscles.
This causes the tissues behind the eyes to expand within the bony orbit (which cannot expand), pushing the eyes forward (proptosis) and compressing structures including the optic nerve and extraocular muscles.
Understanding the difference between hypothyroidism and hyperthyroidism is helpful context for anyone diagnosed with TED. Smoking is the strongest modifiable risk factor for TED: smokers with Graves' disease are approximately 8 times more likely to develop TED than non-smokers, and smoking is associated with more severe disease and worse response to treatment 2.
Radioactive iodine treatment for hyperthyroidism may transiently worsen TED in some patients, which is why concurrent steroid prophylaxis is sometimes recommended.
Thyroid Eye Disease Symptoms
Eye Irritation and Dryness
Early TED often begins with non-specific eye symptoms that can be mistaken for allergies or dry eye syndrome 1:
- Grittiness, scratchiness, or a foreign body sensation in the eye
- Excessive tearing or watering
- Light sensitivity (photophobia)
- Redness of the conjunctiva (the white of the eye)
- Dryness and irritation
These symptoms result from early inflammation of orbital tissues and incomplete eyelid closure even at this stage. Many patients are initially treated for allergies or dry eye before TED is recognized.
Eyelid Changes
Characteristic eyelid changes in TED include:
- Upper eyelid retraction: The upper lid is pulled upward, exposing more of the sclera (white) above the iris — this is often the most visually noticeable early sign
- Lower eyelid retraction: Similarly, the lower lid may sit below the iris
- Lid lag: When looking downward, the upper lid moves more slowly than the eye — visible as a delay in following gaze
- Puffy or swollen eyelids: Upper eyelid swelling and puffiness around the eyes, especially upon waking
Lid retraction exposes more of the cornea to air and reduces the protective blink reflex, contributing to dryness and corneal irritation.
Proptosis (Bulging Eyes)
Proptosis — the forward displacement of one or both eyeballs — is the most recognized hallmark of TED and occurs as orbital tissue volume increases 2. It may be:
- Bilateral (both eyes) or, less commonly, unilateral (one eye, which may be more alarming)
- Measurable with an exophthalmometer (a device that quantifies eye protrusion)
- Associated with a feeling of pressure or fullness behind the eyes
- Cosmetically concerning and often distressing to patients
Proptosis can impair complete eyelid closure during sleep, causing corneal exposure — a serious complication requiring treatment.
Double Vision (Diplopia)
Double vision occurs when the extraocular muscles — those controlling eye movement — become inflamed and fibrotic (scarred), limiting coordinated eye movement 1. Initially, diplopia may occur only in extreme gaze positions; later, it can be present in primary gaze (looking straight ahead). This symptom significantly impairs driving, reading, and daily function.
It may fluctuate with disease activity and often partially resolves with treatment, though some muscle fibrosis may be permanent.
Optic Neuropathy (Vision Threat)
The most serious complication of TED is dysthyroid optic neuropathy (DON), which occurs when the enlarged extraocular muscles compress the optic nerve at the orbital apex 2. Symptoms include:
- Reduced visual acuity (blurred vision that does not clear with blinking or glasses)
- Color desaturation (colors appear less vibrant, particularly red)
- Visual field defects
- Relative afferent pupillary defect (RAPD) — detectable on examination
DON is a medical emergency. Without prompt treatment — which may include high-dose corticosteroids, orbital decompression surgery, or radiation — permanent vision loss can occur.
Active vs. Inactive Phase of Thyroid Eye Disease
TED follows a characteristic biphasic course:
- Active phase: Inflammation is ongoing. Symptoms worsen progressively over months (typically 12–18 months) as orbital tissues enlarge. This is the window for immunosuppressive treatment to reduce inflammation and prevent permanent changes.
- Inactive phase: Inflammation subsides. Symptoms may partially improve; however, structural changes — proptosis, muscle fibrosis, lid retraction — may persist permanently and may require surgical correction 1.
The Clinical Activity Score (CAS) is used by ophthalmologists to assess whether TED is in the active phase. Treatment decisions depend heavily on disease activity, severity, and the risk of optic neuropathy.
Treatment Overview
Treatment depends on disease severity and activity:
- Mild TED: Lubricating eye drops, UV-protective sunglasses, head-of-bed elevation to reduce morning puffiness, and smoking cessation
- Moderate-to-severe active TED: Intravenous glucocorticoids (high-dose steroids) are first-line; orbital radiation is used in some cases. Teprotumumab — an IGF-1R (insulin-like growth factor 1 receptor) inhibitor — received FDA approval in 2020 as the first medication specifically approved for TED. Clinical trials showed significant reductions in proptosis and diplopia 2.
- Vision-threatening TED: Emergency orbital decompression surgery to expand the orbit and relieve optic nerve compression
- Rehabilitation surgery (after inactive phase): Orbital decompression, strabismus surgery for diplopia, and eyelid surgery are performed sequentially when the condition is stable
Patients managing TED alongside thyroid hormone replacement should review thyroid medication side effects with their endocrinologist, as dose changes can affect disease activity. All treatment decisions should be made by an ophthalmologist experienced in TED, ideally in a multidisciplinary team with an endocrinologist.
When to See a Doctor
Seek immediate emergency eye care if you experience:
- Sudden worsening of vision, blurred vision, or visual field loss
- Marked pain behind the eyes
- Inability to move the eye in one or more directions
- Severe corneal irritation or redness with vision changes
See an ophthalmologist promptly (within days) if you have a known Graves' disease diagnosis and develop:
- New eye symptoms including grittiness, double vision, eyelid changes, or noticeable bulging of one or both eyes 1
- Any change in existing eye symptoms during radioactive iodine treatment for hyperthyroidism
See your endocrinologist and an ophthalmologist for a baseline eye examination if you have been newly diagnosed with Graves' disease — even without eye symptoms — as subclinical TED can be present and benefit from monitoring 2.
Because TED often coexists with broader thyroid dysfunction, our thyroid symptom quiz can help you assess other thyroid symptoms you may not have connected to the same underlying condition.
For those newly diagnosed, understanding how to test cortisol levels and other hormonal markers may be helpful context, as autoimmune thyroid conditions sometimes coexist with adrenal issues.
Frequently asked questions
Does thyroid eye disease go away on its own?
Thyroid eye disease follows a natural course: an active phase of progressive inflammation lasting typically 12–18 months, followed by an inactive phase where inflammation stabilizes or subsides. In mild cases, some spontaneous improvement occurs after the active phase. However, structural changes such as proptosis, muscle fibrosis, and lid changes may persist and require surgical correction. Active-phase treatment with immunosuppressive therapy or teprotumumab is aimed at limiting these permanent changes.
Can you have thyroid eye disease without hyperthyroidism?
Yes. While TED is most commonly associated with Graves' disease (hyperthyroidism), it can occur in people with Hashimoto's thyroiditis (hypothyroidism) and even in people with normal thyroid function (euthyroid Graves' orbitopathy). The underlying mechanism is autoimmune and driven by TSH receptor antibodies and IGF-1R antibodies rather than by thyroid hormone levels directly.
Is smoking really linked to thyroid eye disease?
Yes — smoking is the most powerful modifiable risk factor for developing and worsening thyroid eye disease. Research indicates smokers with Graves' disease are approximately 8 times more likely to develop TED than non-smokers, and smoking is associated with more severe disease, worse outcomes with treatment, and higher rates of optic neuropathy. Smoking cessation is a critical component of management alongside medical treatment.