An aura is a visual disturbance that some people experience just before the onset of a migraine or epileptic seizure. Auras can take many different forms, but often involve seeing shimmering lights, spots, or zigzagging lines. Some people describe auras as a “visual migraine.” While auras themselves are harmless, they can be a warning sign that a severe headache or seizure is imminent. Understanding what you might see during an aura can help you identify when one is happening and take steps to minimize your symptoms.
Common Visual Auras
Here are some of the most common visual disturbances that people report seeing during an aura:
Zigzag Lines
One of the most classic aura symptoms is seeing zigzagging lines in your field of vision. These jagged lines typically start out narrow and then get progressively wider. They often shimmer and appear in grayscale, sometimes forming a curved or nested C shape. The lines may last 5-30 minutes and move across your field of vision.
Blind Spots
You may notice a blind spot or dark area blocking part of your vision during an aura. These blind spots often start out small and increase in size over time. They may oscillate, pulse, or sparkle around the edges. The blind spot generally affects just one eye.
Fortification Spectrums
Some people see fortification spectrums, which are zigzag lines that look like the battlements around a castle. The fortification spectrum often starts as a small shimmering spot that expands outward into a complex geometrical pattern with angled lines. The lines have a starburst or semicircular appearance radiating from the central spot.
Flashing Lights
Flashing or flickering lights are also common during auras. You may see sparks, stars, or strobe-like flashes across your field of vision. The flashes may appear white or in different colors. Some people describe it as seeing “heat waves” rising off a hot road.
Kaleidoscope Images
Your aura might make normal objects or scenery appear distorted, fragmented, or psychedelic. Straight lines may appear wavy, surfaces may shimmer or breathe, and colors can become brighter, muted, or mix together kaleidoscope-style. The visual distortions are often localized to just part of your field of vision.
Less Common Aura Types
While scintillating zigzag lines and blind spots are the most reported auric visions, some people experience:
Geometric Patterns
Seeing geometric shapes, grids, or checkerboard patterns during an aura is possible. The geometric visuals often start centralized and radiate outward. The shapes may be still or moving.
Alice in Wonderland Syndrome
This involves objects appearing bigger, smaller, closer, or farther away than they really are. For example, your hand may look gigantic or the room may seem to stretch out. It distorts your perception of size and distance.
Tunnel Vision
Your peripheral vision narrows during the aura, making it feel like you are looking through a tunnel. Your field of vision becomes more restricted and blackened around the edges.
Micropsia and Macropsia
Micropsia makes objects appear miniaturized, while macropsia makes them look gigantic. For example, a car may look the size of a toy car or a house may appear three stories taller. These size distortions are less common than other aura visions.
Afterimages
You continue “seeing” an object or scene even after it has been removed from your field of vision. For example, you might stare at a light bulb and then continue to see the glowing filament even after you look away. These lingering afterimages can occur during an aura.
What Colors Are Seen During Auras?
Auras often appear in grayscale, featuring black and white zigzag lines, spots, or shapes. However, some people do report seeing colors during their auras, including:
| Color | Description |
|---|---|
| White | Whitish or silver shimmering light |
| Yellow | Shimmering dots or stars |
| Red | Heat wave appearance |
| Green | Jagged zigzag lines |
| Blue | Fortification spectrums |
| Purple | Geometric patterns or grids |
| Orange | Flickering or pulsing lights |
The colored visual disturbances often flare up and then fade out during the aura. The intensity and exact shades can vary between different episodes for the same person.
What Order Do Aura Symptoms Appear?
While auras are highly individual, the symptoms often progress in the following order:
1. You may experience prodromal symptoms like mood changes, food cravings, or neck stiffness for up to 24 hours beforehand.
2. The visual disturbances start, usually centralized in one area of vision. Zigzag lines, shimmering lights, or blind spots appear and slowly increase in size.
3. The aura expands outward across the field of vision over 5-30 minutes. Objects may appear distorted. There may be flashing lights or afterimages.
4. The aura peaks and plateaus for a few minutes. Symptoms may waver in intensity.
5. The aura gradually recedes and central vision is restored. Peripheral symptoms linger longer.
6. The aura fully dissipates after roughly 30 minutes total, leaving you with a mild headache which may or may not progress to a migraine.
How Long Do Auras Last?
Most auras last between 5 and 60 minutes. The most common duration is about 30 minutes from start to finish. Symptoms often take around 10 minutes to fully ramp up and another 10 minutes to fade away. The peak aura intensity holds for up to 30 minutes in some cases.
Everyone experiences a different aura timeline. Your episodes may be shorter or longer. But aura duration over 1-2 hours is uncommon and may signal something more serious.
Approximate Aura Timeline:
| Stage | Duration |
|---|---|
| Prodrome | Up to 24 hours before |
| Onset | 5-10 minutes |
| Expansion | Up to 20 minutes |
| Peak | 5-30 minutes |
| Recovery | 10-20 minutes |
| Total Duration | 5 minutes – 1 hour |
Keeping notes on your aura timelines, symptoms, and triggers can help identify patterns and prepare for future episodes.
What Causes Auras?
Auras are caused by abnormal electrical activity in the brain. Areas of the brain cortex temporarily become overexcited and fire off signals that the visual processing centers perceive as flashes of light, zigzags, or geometric patterns.
In migraine sufferers, this electrical hyperactivity typically starts at the back of the brain and then spreads forward in a “cortical spreading depression.” As the wave of hyperactivity travels across the visual cortex, it triggers aura symptoms.
With focal (partial) seizures, the excessive firing originates in just one area of the brain. It activates parts of the cortex involved in processing sight, smell, hearing or other senses, producing auras.
Are Auras Dangerous?
Auras themselves are not directly dangerous or damaging. They are merely symptoms of abnormal brain activity. However, understanding your aura can help:
- Predict and prevent migraines by taking early medication
- Get to safety before an impending seizure
- Avoid driving if your vision is compromised
- Seek emergency help for very prolonged auras or loss of consciousness
Auras linked to seizure activity, stroke, or bleeding in the brain are more concerning. Call your doctor if your episodes are prolonged, getting worse, or accompany serious symptoms.
How Are Auras Diagnosed?
Doctors diagnose auras based on your reported symptoms. They will ask detailed questions about:
- The types of visual distortions you experience
- Where the symptoms start and how they spread
- How long episodes last
- Any provoking factors or early warning signs
- Associated migraine or epilepsy symptoms
Your doctor may order tests like an EEG, CT, or MRI scan to rule out underlying neurological disorders. But in many cases, a detailed history provides enough information to confirm an aura diagnosis.
Can Auras Be Prevented or Treated?
The best treatment focuses on preventing the migraines or seizures that follow an aura. Options may include:
Migraine Medications
Taking abortive medications like triptans or ergots at the earliest aura or prodrome symptoms can stop many migraine attacks before they fully develop.
Anti-seizure Drugs
If you experience recurrent seizures, anti-epileptic medications can help reduce frequency and intensity. This in turn decreases seizure-related auras.
Identify and Avoid Triggers
Things like stress, hormones, fasting, poor sleep, dehydration, and flickering lights can trigger episodes for many people. Avoiding triggers where possible may reduce auras.
Biofeedback Training
This teaches you to consciously control things like breathing, heart rate, and temperature to generate relaxation. Some people find it helps limit migraine auras when practiced regularly.
Supplements
Options like feverfew, magnesium, B2, and coenzyme Q10 may help prevent migraine-related auras for some sufferers. But research is still limited.
When to See a Doctor
You should make an appointment with your doctor if you experience:
- Your first aura
- A major change in your aura symptoms
- Increasing frequency or severity of episodes
- Prolonged auras lasting over 1 hour
- Auras without typical migraine or seizure follow-up
- Loss of consciousness, confusion, numbness, or weakness
In some cases, auras may signal issues like stroke, hemorrhage, or tumors needing emergency care. Getting checked out can identify any underlying cause requiring specific treatment.
Conclusion
An aura is a visual disturbance that serves as an early warning sign of an oncoming migraine or seizure. While the spectrum of possible symptoms is wide, common experiences include seeing zigzag lines, flashing lights, shimmering blind spots, or geometric patterns. Auras are caused by abnormal electrical activity in the brain and are usually harmless in themselves. But paying attention to your aura symptoms and timeline allows you to take medication or precautions to minimize your discomfort from migraines or seizures. With an accurate diary of your auras, doctors can better diagnose and treat the underlying condition. While auras can’t always be prevented, recognizing them promptly gives you the best chance of mitigating their effects.
