What Causes Ocular Migraines?

Quick answer: An ocular (or retinal) migraine is caused by a brief spasm or drop in blood flow to the vessels behind one eye, producing short-lived vision changes such as flickering, a blind spot, or temporary vision loss in that single eye, usually lasting under an hour. It is different from a migraine with aura, which affects both eyes. Because the same symptoms can signal something more serious, any sudden vision change should be evaluated by an ophthalmologist.

What causes an ocular migraine?

Ocular migraines happen when the blood vessels supplying the retina briefly narrow, reducing the oxygen and nutrients the eye needs. When the vessels relax, vision returns to normal, usually with no lasting damage. True ocular (retinal) migraine is relatively rare, and it almost always affects the same eye each time.

Common triggers include:

• Stress and fatigue, or too little or too much sleep
• Skipping meals or low blood sugar
• Dehydration
• Alcohol
• Smoking
• Hormonal changes
• Exercise, bending over, or sudden exertion
• Excessive heat or changing weather
• High blood pressure

Ocular migraines are more common in women, in people under 40, and where there is a family history. The risk can also be higher alongside certain conditions, including lupus, epilepsy, sickle cell disease, and arteriosclerosis.

Symptoms of an ocular migraine

• Diminished or lost vision in one eye only
• Usually lasts less than 60 minutes, often 10 to 20
• Vision loss may begin centrally and spread, or affect peripheral vision
• Flashes of light or a mosaic-like pattern
• A headache before, during, or after the visual episode
• Nausea

How ocular migraines are diagnosed and treated

Diagnosis is based on your symptom history together with a comprehensive dilated eye exam, and sometimes blood tests or imaging to rule out other causes. You may be asked to keep a headache journal to help identify your triggers. Treatment is tailored to you and can range from over-the-counter pain relief such as ibuprofen, naproxen, or acetaminophen to prescription options such as beta-blockers, calcium channel blockers, tricyclic medications, or anti-seizure medication, alongside steps to avoid your personal triggers. Learn more on our ocular migraine care page.

When to treat it as an emergency

Sudden vision loss is not always a migraine. The same symptoms can be caused by more serious conditions, including a TIA (transient ischemic attack), seizures, a cluster headache, or migraine with aura. Until you have a confirmed ocular migraine diagnosis, treat any sudden vision change as a medical emergency and seek care right away. If you have already been diagnosed and an episode behaves differently than usual, such as both eyes being affected, lasting longer, or causing worse vision loss, get evaluated promptly.

Get an expert diagnosis at West Boca Eye Center

Only an ophthalmologist can confirm an ocular migraine and rule out more serious causes. At West Boca Eye Center in Boca Raton, we perform the testing and imaging needed to pinpoint what is happening and build a treatment and prevention plan. Learn more about our ocular migraine care or schedule an evaluation with our team.