Hyperthyroidism is a condition in which the thyroid gland produces too much of the thyroid hormone, causing symptoms like weight loss, irregular heartbeat, hand tremors, and more. Hyperthyroidism can also result in symptoms that affect the eyes in a variety of ways. Luckily, if this condition impacts the eyes there are a few treatments that can help, including infusion therapy, corticosteroids, orbital radiotherapy, and eyelid retraction repair. If you’re worried you may have hyperthyroidism, here are 6 eye symptoms and signs to look out for:

1. Eyelid retraction
Eyelid retraction is the most common eye sign of hyperthyroidism. This can be attributed to increased stimulation of the Muller’s muscle, which functions to keep elevation of the upper eyelid, by the thyroid hormone. It could also potentially be caused by scar tissue forming between the muscles and tissue around the eye.

2. Dry and gritty feeling
With hyperthyroidism, your eyes may experience a dry and gritty feeling that is itchy and scratchy—this is due to the inflammation of the tissues surrounding the eyes. The constant pressure of the inflammation is what causes the strange sensation and may also result in redness and swelling. You may want to speak to your doctor about getting eye drops.

3. Sensitivity to light
If you’re experiencing dry eyes as a result of hyperthyroidism, you may also develop a sensitivity to light. This is because dry eyes can create an irregular surface of the eye that causes light to scatter in multiple directions. This scattered light can then cause feelings of discomfort and pain. Furthermore, with the swelling and irritation you experience, you may blink less or find it hard to close your eyes which can also lead to dry eyes and contribute to light sensitivity. To deal with light sensitivity, you should wear sunglasses or look into prosthetic contact lenses that can block excess light from entering your eye, thus reducing discomfort.

4. Watery eyes
On the other side of dry eyes, some individuals with hyperthyroidism may experience the opposite—watery eyes. With this condition, your eyes may produce more tears than normal and result in watery eyes. Your eyes may also become sore, swollen, and red.

5. Bulging eyes
A characteristic symptom of hyperthyroidism is bulging eyes, or eyes that seem to be pushed forward and present a ‘staring’ look. This is a result of the inflammation and swelling of the muscles and tissues around the eyes that push the eyes forward.

6. Blurred or double vision
As a result of bulging eyes and inflammation of the eye muscles, you may experience blurred or double vision. This is because the inflammation shifts the eye and causes your vision to become out of line as well as decreases movement of the eye.