When vision problems are actually migraine attacks

Imagine suddenly seeing bizarre patterns of light: perhaps they flicker, zigzag through the air, flash in different colors, or shimmer in shapes you might see through a kaleidoscope. These visual phenomena occur out of the blue and disappear soon afterward. And if you see them periodically, they might be the result of certain types of migraine.

What is migraine?

Migraine is a condition typically characterized by a debilitating headache, usually on one side of the head, that can last for hours or days. It’s often accompanied by nausea, vomiting, brain fog, and sensitivity to light and sound.

For about 30% of people who have migraine, the episode begins with what’s known as aura — unusual light patterns or distorted vision in both eyes, often in just half of each eye’s field of vision. “It’s believed to be caused by a wave of brain activity that temporarily interrupts normal brain function,” explains Dr. Tais Estrela, a neuro-ophthalmologist at Harvard-affiliated Massachusetts Eye and Ear.

Aura often goes away within an hour and is usually followed by headache.

Migraine aura without headache

For some people with migraine aura, the headache never comes. Yet they still experience strange, sudden light patterns or darkened vision, and they might also have other migraine symptoms, such as nausea and light sensitivity.

This type of migraine, called “silent migraine,” can still be debilitating. And a first-time silent migraine attack can be mistaken for a stroke, which also can cause vision changes or loss.

Ocular migraine

Another type of migraine that causes disabling visual disturbances affects the retina (tissue in the back of the eye that sends light signals to the brain). This type is called retinal or ocular migraine.

Like migraine aura, ocular migraine also brings on flickering lights or darkened vision, but usually in only one eye, and for a much different reason. “One theory about ocular migraine is that it may be caused by a brief narrowing of blood vessels in the retina. This phenomenon doesn’t cause eye pain, and it might not occur with the classic migraine headache,” Dr. Estrela says.

When flashes occur

Seeing sudden light patterns for more than a few minutes shouldn’t be chalked up to migraine automatically. The lights may signal a stroke if vision changes are accompanied by weakness or facial drooping on one side of your body, confusion, or difficulty speaking. If the lights appear in just one eye, it could be that blood flow in retinal arteries is blocked or the retina has detached, which can cause permanent vision loss. Go to the emergency room in both cases.

If you’ve been experiencing episodes of light patterns for some time — whether daily or occasionally — make an appointment with your eye doctor as soon as possible to determine if migraine is to blame.

Treatment

Doctors use various approaches to try to prevent ocular or silent migraine episodes. For example, they might prescribe medications such as the calcium-channel blocker verapamil or an anti-seizure medication, such as topiramate, depending on the migraine features. Doctors might also suggest magnesium supplements. “The theory is that magnesium helps reduce the frequency and severity of migraine attacks, potentially by blocking pain-transmitting chemicals in the brain,” Dr. Estrela says.

Drugs called triptans might help soothe a silent migraine attack after it starts, especially if it’s accompanied by other migraine aura symptoms. We don’t have a way to stop an ocular migraine attack as it’s occurring.

What you can do

For many people, the only way to cope with an ocular or silent migraine episode is to wait it out. “Rest and avoid visual stimulation, which makes things worse,” Dr. Estrela advises. “Go to a dark, quiet room, and drink some water if you’re dehydrated.”

Other approaches include meditating, reducing stress, and avoiding triggers that seem to bring on your symptoms, such as dehydration, too little sleep, alcohol, and nitrates (in soy sauce, for example) or preservatives (in many packaged foods).

If you’re unsure of your triggers, Dr. Estrela suggests writing down the circumstances prior to each episode to find common patterns, or typing circumstances into a smartphone app with an algorithm that finds the patterns for you.

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