Ocular Migraine: Symptoms, Causes and When It's an Emergency

An ocular migraine is a migraine that shows up in your vision: flashing lights, zigzag lines or a blind spot that build over several minutes and usually clear within an hour. The name covers two things: a migraine aura, which usually affects both eyes, and retinal migraine, a rare type that causes temporary vision loss in one eye. Call 911 for sudden loss of vision in one or both eyes, even if it comes back, for sudden double vision, for a first aura or one that's different from your usual ones, and for any vision change with stroke signs such as face drooping, weakness or trouble speaking. New flashes, a shower of new floaters or a curtain over part of your vision mean calling us right away for a same-day urgent eye care visit, or going to an emergency room when we're closed.

Key takeaways

An ocular migraine affects what you see, with flashes, zigzags or a blind spot that grow over several minutes and usually go away within an hour.
The name can mean a migraine aura, usually in both eyes, or retinal migraine, a rare type with temporary vision loss in one eye.
A familiar aura that clears within an hour needs no emergency visit, and if one starts while you're driving, pull over until your vision fully clears.
Call 911 for sudden vision loss in one or both eyes, even if it comes back, or for a first aura or one unlike your usual ones.

What is an ocular migraine?

Ocular migraine is an everyday term for two different conditions. One is a migraine aura, a set of temporary symptoms that can come before a migraine headache. According to the National Institute of Neurological Disorders and Stroke, aura symptoms usually affect vision (dots, zigzags or sparks), though they can also change a person's ability to speak.

The other is retinal migraine, which StatPearls defines, under both names, as a temporary blind spot or loss of vision in one eye. Because the same name is used for both, it helps to know which one you've had.

Migraine with aura is common. Migraines affect about 12% of the population, and about 25% of cases include auras. Retinal migraine is rare, and how many people have it is not known.

What are ocular migraine symptoms?

A visual aura usually starts as a small area of lost vision or as bright lines or shapes, then spreads until it covers a quarter or half of what you can see. People describe:

Flashes of bright light, lines or shapes, with some loss of vision
Zigzag lines, dots or sparks
A shimmering blind spot, which doctors call a scintillating scotoma

The symptoms build gradually, over 5 minutes or more, and usually clear within 60 minutes, with central vision coming back first. An aura usually starts about 10 minutes to an hour before the headache, and some people get the visual symptoms with no headache at all.

Migraine with aura or retinal migraine: how can you tell?

Which eye is involved is the main clue. Vision trouble in only one eye is less common with migraine aura, and the first step in checking for retinal migraine is to work out whether the symptoms are in one eye or both.

You can check during an episode by covering one eye, then the other. If the zigzags are still there whichever eye you cover, both eyes are seeing them, which fits a migraine aura. If they disappear when one particular eye is covered, the problem is in that eye. A stroke can affect the vision of both eyes too, so this check never replaces the 911 rules below.

Feature	Migraine with aura	Retinal migraine
Eyes affected	Usually both	One eye
How common	About 25% of migraine cases	Rare
How long	Builds over 5 minutes or more, clears within an hour	Episodes can last 5 to 20 minutes
What you see	Zigzags, flashing lights, a spreading blind spot	A blind spot or loss of vision in one eye

Retinal migraine is diagnosed only after other causes of one-eye vision loss are ruled out. Those include amaurosis fugax, a brief loss of vision caused by a clot that travels from the carotid artery in the neck or from the heart, and giant cell arteritis.

Giant cell arteritis is an inflammation of the arteries, usually in the scalp, neck and arms, and it almost always affects people over 50. It can cause headaches, tenderness over the temples, jaw pain, and double vision or vision loss; without early treatment, there is a risk of permanent vision loss or stroke.

Retinal migraine itself can cause permanent vision loss, so new vision loss in one eye is an emergency even if it clears.

What causes ocular migraines?

The visual aura comes from a wave of nerve-cell activity that spreads across the cortex, the brain's outer layer. Doctors call it cortical spreading depression. Migraine happens in both children and adults, and females have it more often than males.

Several factors can set off an attack. The triggers NINDS lists include:

Sudden changes in the weather or your surroundings
Too much or not enough sleep
Emotional stress and physical strain
Low blood sugar or skipped meals
Drinking too much alcohol, and tobacco
Hormonal changes
Bright or flashing lights, loud or sudden noises and strong smells
Motion sickness and some medicines

When are ocular migraine symptoms an emergency?

Call 911 for sudden loss of vision in one or both eyes, even if it comes back, and for any change in your vision that comes with a stroke warning sign:

Face drooping, or numbness or weakness of the face, arm or leg, especially on one side
Trouble speaking or understanding speech, or sudden confusion
Sudden loss of balance, trouble walking or dizziness
A severe headache with no known cause

Do this even if you think it's a migraine, and call 911 too if it's your first aura or it feels different from your usual ones: a clot from the carotid artery or the heart can cause the same brief loss of vision in one eye, and StatPearls advises an emergency room visit for vision loss that looks like darkness. Don't wait to see whether it clears. Note the time your symptoms started.

Call 911 too for double vision that starts suddenly, which the American Stroke Association lists among stroke warning signs, and for double vision or a drooping eyelid that comes with a pupil that looks different, eye pain or a severe headache, even if it feels like one of your migraines. A large, growing brain aneurysm can press on nerves and cause pain above and behind the eye, a widened pupil and double vision.

Sudden, severe eye pain with nausea, a red eye, blurred vision, a headache or halos around lights can be acute angle closure, a type of glaucoma that is a medical emergency: call us immediately during office hours, or go to an emergency room.

Call our office right away for a same-day exam, or go to an emergency room when we're closed, if you notice a dark curtain or shadow over part of your vision, new flashes of light, or a shower of new floaters (small dark spots or squiggly lines that drift across your vision). These can be signs of a retinal detachment, which is a medical emergency.

Our office hours are Monday 10 to 5, Tuesday through Friday 8 to 5. Call 310-828-2010 first so we can triage you; our page on floaters and flashes covers those symptoms in more detail.

How are ocular migraines treated?

The aura passes on its own, usually within an hour. A familiar aura, like your usual ones, that clears within an hour doesn't need an emergency visit; tell us at your next exam. If one starts while you are driving, pull over until your vision has fully cleared.

Treatment for the migraine itself comes from your primary care doctor or a neurologist. There is no cure for migraine, but treatments can help manage symptoms. Over-the-counter pain relievers such as ibuprofen, aspirin or acetaminophen can ease the pain of less severe attacks, and triptans such as sumatriptan and zolmitriptan are a common prescription treatment. People who have attacks once a week or more are usually prescribed treatment to prevent them.

Retinal migraine is managed differently: StatPearls advises doctors to avoid triptans, ergots and beta-blockers in migraines that cause temporary vision loss. If you've had vision loss in one eye, tell the doctor who treats your migraines, and don't stop a prescribed medicine on your own.

What happens at an eye exam after an ocular migraine?

A dilated eye exam is how an eye doctor checks for a retinal detachment. At Cohenmehr Optometry the urgent work-up includes a dilated retinal exam, retinal photography and OCT imaging, which takes pictures of the retina with a special machine. Our optometrists in Los Angeles add visual field testing when it's needed.

If your eyes are healthy and the episode fits a migraine aura, the next step for the headaches is your primary care doctor or a neurologist. If we find a retinal problem, the referral to a retina specialist and your records go out the same day. Your scans also become a baseline, so later changes are easier to spot at your comprehensive eye exams.

Questions patients ask

Is an ocular migraine the same as an eye stroke?

No. An ocular migraine is a temporary change in vision caused by a migraine. An eye stroke, or central retinal artery occlusion, happens when blood flow is blocked to the main artery of the eye. It typically causes painless, immediate vision loss in that eye, and fewer than 20% of people regain functional vision in it. If you suddenly lose vision in one or both eyes, even if it comes back, call 911 instead of waiting to see whether it's a migraine.

Can a migraine cause tunnel vision?

A migraine aura can take away part of your vision for a short time. It usually starts as a small area of vision loss or bright lines, spreads to a quarter or half of your field of vision, and clears within about an hour, with central vision returning first. Side vision that narrows slowly over time is how glaucoma usually starts. Sudden loss of vision, even if it comes back, is a reason to call 911.

Are eye floaters and headaches connected?

Usually they have different causes. Floaters are small dark shapes that drift across your vision, and they usually come from normal changes in the eye, while a migraine aura starts in the brain. A lot of new floaters that appear suddenly, flashes of light, or a dark shadow like a curtain can mean a retinal tear or detachment. Call your eye doctor right away: we see these the same day during office hours, and when the office is closed, go to an emergency room.

Does migraine with aura raise your risk of stroke?

It can. The CDC notes that the risk of ischemic stroke, a stroke from a blocked blood vessel, is higher in women who have migraine with aura than in women without migraine. Strokes caused by migraine are still rare, at a reported 0.8 to 3.4 per 100,000 people a year. For people who have migraine with aura, the CDC rates birth control that contains estrogen (combined pills, the patch and the ring) as an unacceptable health risk. Don't stop your birth control on your own: tell the doctor who prescribes it that you get auras.

Sources

Written by

Dr. Kevin Cohenmehr, OD

Medical eye care: glaucoma, diabetic eye exams, macular degeneration and eye infections, plus vision therapy for children. A graduate of UCLA and SUNY College of Optometry.

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