Ocular Migraine: Symptoms, Causes and When Zigzag Vision Needs a Doctor

The short answer: what most people call an ocular migraine is a migraine visual aura. A flickering spot appears, grows into a shimmering zigzag band, and fades within about an hour, with or without a headache. It is usually harmless. The key is knowing the few signs that point to something else, because some eye and blood-flow problems can look similar at first.

What is an ocular migraine?

"Ocular migraine" is an everyday term rather than a formal diagnosis, and it gets used for two different things:

• Migraine with visual aura (by far the most common). The light show starts in the brain, not the eye, so it shows up in the same part of your view in both eyes. About 9 out of 10 people whose migraines come with an aura have this visual kind.
• Retinal migraine (rare). Short bouts of dimming or blind spots in one eye only, usually in people who already have migraines. Because many other conditions cause one-eye vision loss, doctors only call it retinal migraine after those have been ruled out.

Headache specialists now prefer the terms "migraine with aura" and "retinal migraine," but "ocular migraine" is what most of our patients type into a search bar, so we use it here.

Ocular migraine symptoms

A typical visual aura follows a recognizable pattern:

• a small bright, flickering or shimmering spot, often near the center of your view;
• a C-shaped band of zigzag or herringbone lines that slowly spreads toward one side, sometimes in rainbow colors;
• a blurry, wavy or missing patch inside the band, so words on a page or parts of a face seem to drop out;
• a gradual build over several minutes, then a slow fade. Most episodes last 20 to 30 minutes, and almost all are gone within an hour.

Some people also feel tingling in a hand or the face, or have trouble finding words. A headache, nausea or sensitivity to light and sound may follow within the hour, or there may be no headache at all. Vision goes back to normal afterward.

The cover-one-eye test

If it happens again, try this while the aura is still there: cover your right eye, then your left. A migraine aura looks the same whichever eye is covered, because it comes from the brain's visual centers. If the zigzags or blind spot are only in one eye, it is not a typical aura and you should be seen the same day. Jot down the time it started and how long it lasted; those details help your doctor.

What causes ocular migraines?

An aura is linked to a slow wave of electrical and chemical activity, called cortical spreading depression, that moves across the visual part of the brain. The wave itself does not harm the brain. Migraine often runs in families and is more common in women. Common triggers include:

• stress, or the let-down after a stressful stretch;
• too little sleep, or oversleeping;
• skipped meals and dehydration;
• bright, glaring or flickering light, including long screen sessions;
• strong smells or smoke;
• alcohol (especially red wine) and too much caffeine;
• hormone changes, such as around a menstrual period.

A simple diary of what you ate, how you slept and what you were doing before each episode is often the fastest way to spot your own triggers.

Ocular migraine or something more serious?

Several conditions can start with flashing lights or a patch of missing vision. These clues help tell them apart:

• Retinal tear or detachment. Flashes from the retina are quick, like a camera flash or lightning streak at the edge of vision, and they happen in one eye. They often come with a shower of new floaters, or a shadow or curtain that does not go away. Our guide to floaters and flashes explains which of these need a same-day visit.
• A mini-stroke (TIA) or blocked blood flow to the eye. Sudden dimming or blackout of vision in one eye, often painless and lasting minutes, can be a warning sign of stroke, especially after age 50 or with high blood pressure, diabetes, high cholesterol or smoking.
• Stroke. Vision loss together with face drooping, arm or leg weakness, numbness on one side, confusion or slurred speech is an emergency.

Call 911 for sudden vision loss with weakness, numbness, face drooping or trouble speaking, or the worst headache of your life. Do not wait to see if it passes.

When to see an eye doctor about an ocular migraine

Book an exam, or call us the same day, if:

• this is the first time you have had visual symptoms like this;
• the change is in one eye only;
• it lasted less than 5 minutes or more than an hour;
• it happened without a headache and you are over 50, or your first aura began after 50;
• your usual auras have changed, are coming more often, or feel different;
• you also notice new floaters, a curtain or shadow, or vision that has not fully come back.

People who have migraine with aura have a slightly higher risk of stroke, so it is also worth telling your primary care doctor about your auras, especially if you smoke or take hormonal medicines.

What we check at your visit

After a first aura, most patients want to know one thing: is my eye healthy? We start with the story: what you saw, which side, how long it lasted and what came with it. Then we dilate your pupils and look closely at the retina and optic nerve to rule out a tear, detachment or signs of blocked blood flow. Retinal photos, OCT scans and a visual field test can show changes too small to see by eye alone; our eye exam technology page shows each one. When the pattern points to the brain or nerves, our neuro-ophthalmic eye exams page explains the added testing we do and how we coordinate with your primary care doctor or a neurologist.

Treatment for migraine itself, including medicines to stop an attack or prevent future ones, is usually handled by your primary care doctor or a neurologist. Our part is making sure the eyes are healthy and that nothing else is being missed. Not sure who to see first? Our article on optometrist or ophthalmologist sorts it out, and you can meet our eye doctors before you come in.

Everyday steps that may help

• Stop and wait it out. If an aura starts, pull over if you are driving and rest until your vision is fully back.
• Keep a steady routine. Regular sleep, regular meals and enough water remove some of the most common triggers.
• Tame bright light and glare. Good sunglasses outdoors help; see our polarized sunglasses guide. Indoors, take screen breaks and lower the brightness; our post on screen time and your eyes has more tips.
• Keep your prescription current. Squinting through an old prescription adds strain on long days. Our custom lens choices page covers computer lenses and tints, and our face shape glasses guide helps you choose a frame you will want to wear.

Other eye symptoms that tend to show up during stressful, short-sleep weeks include a flickering eyelid; see why your eye is twitching. And if it has been a while since your last checkup, here is how often you should get an eye exam.

Frequently asked questions

What does an ocular migraine look like?

Most people describe a small shimmering or flickering spot that slowly grows into a curved band of zigzag lines, often with a blurry or missing patch inside it. The pattern usually drifts toward one side of your view and fades on its own, most often within 20 to 30 minutes and almost always within an hour.

Is an ocular migraine dangerous?

The common kind, a visual migraine aura, is usually harmless and goes away completely. What matters is ruling out look-alikes. Vision changes in only one eye, an aura that lasts more than an hour, a first episode after age 50, or vision changes with weakness, numbness or trouble speaking need prompt medical care.

Can you have an ocular migraine without a headache?

Yes. Some people see the zigzag aura with no headache afterward, which is sometimes called a silent migraine or aura without headache. Because it can be harder to tell apart from other causes, a first episode without a headache is worth a call to your eye doctor or primary care doctor.

How do I know if it is in one eye or both eyes?

While it is happening, cover one eye, then the other. A migraine aura comes from the vision centers of the brain, so it stays the same no matter which eye is covered. If the change disappears when you cover one eye, the problem is in that eye, and you should be seen the same day.

What causes ocular migraines?

A migraine aura comes from a slow wave of electrical and chemical activity moving across the part of the brain that handles vision. Common triggers include stress, too much or too little sleep, skipped meals, bright or flickering light, strong smells, alcohol, too much caffeine and hormonal changes. Migraine also tends to run in families.

Ocular migraine and flashing light checks in Alpharetta

If you have had zigzag lines, flashes or a blind spot and want to be sure your eyes are healthy, we are glad to help. Book online or call 770-776-9000. Reimbold Eye Group is at 4180 Old Milton Pkwy 1-D, Alpharetta, GA 30005.

Live close by? Here is what to expect at our eye exams in Alpharetta.

This article is for general education and is not a diagnosis. If you are worried about a symptom, call us or see a doctor. For sudden vision loss with weakness or trouble speaking, call 911.