Why “Ocular Migraines” Probably Aren’t What You Think
Let’s start with a common story:
You are at work, minding your business, when suddenly your vision starts glitching. Maybe there is a shimmering zigzag crawling across your sight. Maybe a blind spot appears, right in the middle of your sentence. It lasts about 20 minutes, and then… gone. You feel fine afterward. Naturally, you Google it, panic, and end up at your optometrist’s office.
What happens next? You are probably told you had an ocular migraine.
Except here is the problem: in most cases, that label is not technically correct.
The Great Migraine Vocabulary Mix Up
The word migraine covers a lot of ground. Some people get the classic headache: one side of the head throbbing, nausea, light sensitivity, the whole package. But migraines can also show up as neurological symptoms without much or any pain.
The visual fireworks people describe (flashing lights, zigzags, expanding blind spots) are called a migraine aura. These auras come from the brain’s visual cortex, not from the eyes themselves. They usually last 5 to 60 minutes and often fade without leaving a trace.
And auras do not always lead to headaches. In fact, plenty of people only ever get the visual part and then nothing. This is called a silent migraine or an acephalgic migraine.
So why do so many patients get told it is an ocular migraine?
“Ocular Migraine” vs. Reality
The terms ocular migraine and ophthalmic migraine have been floating around for decades. Sometimes they are used to describe a true one eye visual loss from a rare condition called retinal migraine. Other times, they are used to describe the far more common visual aura which actually affects both eyes.
The reality:
Most cases labeled ocular migraine are actually silent migraines with aura, which is a brain phenomenon.
True retinal migraine is exceedingly rare and always affects only one eye.
To put it in perspective:
Silent migraines are thought to affect roughly 1 percent of the general population.
Retinal migraine is far less common, with only a small number of well documented cases in the medical literature.
So if your vision goes wavy or zigzaggy in both eyes for 20 minutes and then clears, the odds strongly favor a silent migraine, not an eye migraine.
What is Actually Happening in the Brain?
Imagine you are the referee of a hockey game. The crowd suddenly starts doing the wave. One section of fans jumps up (just like a group of neurons firing in the brain’s cortex), the next section follows, and the ripple spreads around the arena (the wave of excitation known as cortical spreading depression). Afterward, those fans sit back down (the neurons reset into a recovery phase).
If the wave passes through the section of the arena labeled “visual cortex,” your visual system gets caught up in it. That is when you see zigzags, flashing lights, or blind spots. This is the aura.
Most of the time, the players on the ice stay focused on the game, and you, the referee, just watch the crowd’s wave come and go. But what if the players themselves jump in on the action? In brain terms, that is when the blood vessels and pain pathways get pulled into the process. Suddenly the game is chaos, benches clear, and you as the ref are stuck trying to restore order. That is the throbbing headache, nausea, and light sensitivity.
If the players stay concentrated on the game and it is only the crowd doing the wave, you get the visual show without the pain… the silent migraine.
Why You Hear About Them So Much
Now, for the eye care professionals reading this: you might feel like ocular migraines are everywhere. Patients keep showing up saying they had an ocular migraine last week.
But here is the catch. The group that shows up in an eye clinic is not representative of all migraine patients. People who get aura followed by a disabling headache usually stay home in a dark room. People who get aura without headache often feel well enough to book an appointment, and since it appears to only be an eye problem (no associated headache), they come see you, the eye doctor.
That is selection bias. In an eye care setting, aura without headache is more visible, even though in the general population it is only a small subset of migraine.
The Bottom Line
Migraines are complicated, and the language around them has not always kept pace with what we now understand. What most people call an ocular migraine is usually a silent migraine with aura. While the visual symptoms can be unsettling, they are usually harmless. The rare exception is vision loss in just one eye, which deserves prompt medical attention. Understanding these distinctions helps take some of the mystery out of the experience and gives people a clearer sense of when to seek care.
One last thing to know: the light show from a migraine aura is very different from the flashes you might get if something is going on inside the eye itself, like a retinal tear, detachment, or a vitreous shift. Migraine auras usually look like zigzags or shimmering shapes that grow and fade over 15 to 30 minutes before disappearing. Flashes from retinal problems tend to be quick, bright bursts or streaks of light off to the side, sometimes paired with new floaters or a shadow creeping in from the edge of vision. The first is a temporary brain event, unsettling but not dangerous. The second can be a warning sign of a serious eye issue and needs to be checked right away. Knowing the difference can save you a lot of worry, and in rare cases, even your vision.
Dr. Robert Burke is an optometrist at Calgary Vision Centre. The thoughts, opinions, and analogies shared above are intended for education and entertainment purposes only (think of them like a friendly explainer, not a personal consultation.) Every set of eyes is different, and the right testing protocol depends on your specific vision needs, health history, and lifestyle. So if you're experiencing symptoms or just have questions about your vision, don’t rely on internet content alone, talk to your optometrist or health care provider directly. We’re here to help, but nothing beats an in-person exam with someone who knows your eyes.
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