Yes, thyroid problems can directly affect your eyes. The condition is called thyroid eye disease (TED), and it happens when the same immune system malfunction that attacks your thyroid also targets the tissues behind and around your eyes. Between 80 and 90 percent of people with TED have an overactive thyroid from Graves’ disease, but it can also occur with an underactive thyroid, Hashimoto’s disease, or even normal thyroid levels.
Why Your Thyroid and Eyes Are Connected
Thyroid eye disease isn’t caused by thyroid hormones themselves. It’s caused by your immune system mislabeling the soft tissue around your eyes as a threat. The cells behind your eyes, called orbital fibroblasts, carry some of the same molecular markers found on thyroid cells. When your immune system produces antibodies against the thyroid, those antibodies also latch onto the tissue surrounding your eyes.
Once activated, those orbital cells start producing excess fluid and fat. They swell, creating pressure inside the rigid bony socket that holds your eye. That pressure pushes the eyeball forward and squeezes the muscles that control eye movement, which is why bulging eyes and double vision are hallmark symptoms. Some researchers consider Graves’ eye disease, Graves’ hyperthyroidism, and Hashimoto’s thyroiditis to be three separate autoimmune conditions that tend to occur in pairs rather than one causing the other.
Symptoms to Watch For
Thyroid eye disease usually affects both eyes, though symptoms can be noticeably worse on one side. The most common signs include:
- Bulging eyes (the classic look most people associate with thyroid problems)
- Dry or watery eyes
- Swollen, puffy eyelids
- Light sensitivity
- Eye pain or a feeling of pressure, especially when looking up or to the side
- Double vision
- Difficulty moving your eyes
- Headaches
Over time, some changes can become permanent even after the disease stops progressing. These include eyelid retraction (where the upper lid pulls back, exposing more of the white above your iris), persistent eye bulging, and chronic redness. Blurry vision and double vision can also linger if the eye muscles become scarred in a misaligned position.
It’s Not Just Graves’ Disease
Most people assume thyroid eye disease only happens with an overactive thyroid, but that’s not the full picture. People with hypothyroidism and those with completely normal thyroid levels can develop it too. The eye involvement in these cases tends to be milder, less symmetrical, and less likely to involve the severe muscle swelling seen in hyperthyroid patients. Still, it happens, and it’s worth knowing that “normal” thyroid labs don’t rule out a thyroid-related eye problem.
Active Phase vs. Stable Phase
Thyroid eye disease moves through two distinct phases. The active phase involves ongoing inflammation: redness, swelling, pain with eye movement, and worsening symptoms. Doctors use a 7-point scoring system to assess whether the disease is active, checking for things like eyelid redness, conjunctival swelling, pain when you move your eyes, and how far the eyes protrude. A score of 3 or higher suggests the disease is still actively inflaming your eye tissues.
The active phase typically lasts one to three years before burning out on its own. After that comes the stable (inactive) phase, where inflammation stops but the physical changes it caused, like bulging, lid retraction, or stiff eye muscles, may remain. Treatment decisions depend heavily on which phase you’re in.
When Eye Symptoms Become Urgent
In roughly 3 to 5 percent of cases, swollen eye muscles compress the optic nerve at the back of the socket. This is called dysthyroid optic neuropathy, and it can cause permanent vision loss if it isn’t treated quickly. The warning signs are impaired color vision (colors look washed out or different between your two eyes), swelling of the optic disc visible on an eye exam, and rapidly declining eyesight. If you notice sudden changes in your color perception or a significant drop in vision, that warrants same-day evaluation.
Smoking Makes It Significantly Worse
Smoking is the single biggest modifiable risk factor for severe thyroid eye disease. Current smokers are roughly three times more likely to develop the sight-threatening form of TED compared to non-smokers. Smoking also makes treatment less effective and extends the active inflammatory phase. If you’ve been diagnosed with any thyroid autoimmune condition, quitting smoking is one of the most impactful things you can do to protect your eyes.
Treatment Options
During the active inflammatory phase, the goal is to calm the immune attack. Mild cases are sometimes managed with lubricating eye drops, sunglasses for light sensitivity, and a supplement called selenium. A randomized controlled trial found that selenium supplementation slowed disease progression, reduced eye involvement, and improved quality of life in patients with mild TED. It also appeared to lower levels of the thyroid antibodies linked to the disease. Selenium is an over-the-counter supplement, though it’s worth discussing with your doctor since high doses carry their own risks.
For moderate to severe active disease, a newer treatment has changed the landscape. Teprotumumab is an infusion given every three weeks for about six months that directly blocks the receptor on orbital cells responsible for the swelling and fat accumulation. In long-term follow-up across three clinical trials, about 90 percent of patients saw their inflammation resolve, nearly 70 percent had measurable reduction in eye bulging (averaging about 2.7 millimeters), and roughly 73 percent experienced improvement in double vision. These results held at 72 weeks after starting treatment.
Surgery for Stable Disease
Once the disease has been inactive for at least six months, surgery can address the lasting physical changes. There’s a specific sequence that matters. Orbital decompression (removing bone or fat from the eye socket to let the eyes settle back) comes first if needed. Eye muscle surgery to correct double vision or misalignment comes second. Eyelid surgery to fix retraction or puffiness comes last. Doing them out of order can undo the results of earlier procedures.
Urgent surgery is reserved for situations where the optic nerve is being compressed, the eyeball is at risk of slipping out of the socket, or corneal ulcers aren’t responding to other treatment. Outside of those emergencies, doctors prefer to let the disease stabilize before operating.
Keeping Your Eyes Stable Long Term
Managing your thyroid levels is important, though it won’t stop eye disease entirely since the two conditions run on partially separate tracks. Large swings in thyroid hormone, whether too high or too low, appear to worsen eye symptoms, so consistent treatment and regular blood work help. Beyond that, not smoking, protecting your eyes from wind and dryness, and sleeping with your head slightly elevated to reduce overnight swelling are practical steps that make a real difference in daily comfort.