The thyroid gland, located in the front of the neck, produces hormones that regulate your body’s metabolism (the process by which the body transforms food into energy).

In a small number of people, the thyroid glandproduces either excessive hormone, inadequate hormone, or it inadequately regulates thyroid hormones. An overproduction of thyroid hormone is often associated with a condition known as Graves’ disease; an underproduction is associated with a condition known as Hashimoto’s disease. Atypical regulation of the thyroid hormone can cause problems associated with the structure surrounding the eye and the area within the orbit, and it also can cause subsequent vision problems.

Some eye problems associated with the disease are:

• Eye protrusion: This occurs when the muscles around the eyes swell, which pushes the eye forward. People with this condition look as if they are staring.

• Eyelid retraction: The combination of eyelid swelling and eye protrusion sometimes causes the eyelids to retract and reveal the sclera (the white part) of the eye.

• Dry eye: Because of protrusion and eyelid retraction, the eyes are more exposed to the environment. This causes blurred vision, light sensitivity, dry eye, excessive tearing, irritation, and inflammation.

• Double vision: Muscle swelling may cause double vision.

• Eye bags: Eyelid swelling can cause tissue around the eyes to bulge forward.

These problems are treated by non-surgical and surgical methods. Non-surgical methods include taking steroid medications by mouth to control swelling and inflammation, wearing sunglasses to relieve light sensitivity, and applying lubricating ointment to relieve dry eye. Surgical methods include repositioning the eye muscles, removing scarred tissue, and relieving compression on the optic nerve to preserve sight.

(c) 2007 The American Academy of Ophthalmology