Answer:

Seeing double, also known as diplopia, occurs when you see two images of a single object. This can affect both eyes or just one. Single-eye diplopia is often linked to refractive errors (nearsightedness, astigmatism), dry eyes, cataracts, retinal abnormalities, corneal scarring, or keratoconus.

Double vision affecting both eyes typically indicates a more serious issue, potentially involving the nervous system, eye muscles, or the nerves that control eye movement. Some brain conditions that can cause double vision include brain aneurysms, brain tumors, migraines, increased intracranial pressure (due to infection, bleeding, or trauma), stroke, transient ischemic attack, and giant cell arteritis.

Strabismus (crossed eyes) is another common cause of double vision in both eyes. Conditions like myasthenia gravis and Graves' disease, which affect the muscles controlling eye movement, can also sometimes lead to double vision.

A doctor examines a man's eyes. Illustration: Tam Anh General Hospital

The nerves that transmit signals from the brain to the eyes can also cause diplopia if damaged. Conditions that can damage these nerves include multiple sclerosis (a neurological disease affecting the brain and spinal cord), Guillain-Barre syndrome (a neurological condition causing muscle weakness), and diabetes (which can damage the nerves controlling eye movement, leading to visual disturbances). Factors that can increase the risk of double vision include older age (typically over 60), long-term smoking, and vitamin B1 deficiency.

You haven't specified whether your double vision affects one or both eyes. However, if this unusual symptom persists, you should consult an ophthalmologist for a proper diagnosis and timely intervention. Treatment depends on the underlying cause and the type of diplopia (single-eye or both-eyes). Single-eye diplopia, often stemming from an eye-related problem, can be treated with eyeglasses, contact lenses, or refractive surgery for conditions like nearsightedness and astigmatism; cataract surgery; or artificial tears for dry eyes.

Treatment for double vision in both eyes may include surgery, medication, eyeglasses with prisms to correct the double vision, eye patching exercises, or surgery to adjust eye muscle position.

Dr. Le Thi Huong Giang

High-Tech Eye Center

Tam Anh General Hospital