Have you ever noticed flashing lights, zigzag lines, or partial vision loss lasting a few minutes before disappearing?
If so, you may have experienced a visual aura — a fascinating but generally harmless phenomenon that can occur with or without a migraine headache.

At Oftalis, we often receive patients worried about these sudden visual disturbances. Here we explain what a visual aura is, why it happens, and when to see a specialist.

What is a visual aura?

A visual aura is a temporary visual disturbance caused by brief changes in the brain’s electrical activity, specifically in the visual cortex.
It usually lasts 10–20 minutes, occasionally up to an hour, and disappears completely without aftereffects.

Typical visual aura symptoms include:

  • Zigzag or shimmering lines
  • Flashing or sparkling lights
  • Partial loss of vision (scotoma)
  • Distorted images, as if seen through water or a kaleidoscope

Some people experience aura without headache, known as silent migraine.

What causes a visual aura?

Its exact cause is not fully understood, but it’s believed to be linked to a wave of abnormal electrical activity in the brain (called cortical spreading depression) that temporarily affects the visual area.
It’s not dangerous, though it can be visually striking.

Common triggers include:

  • Stress and anxiety
  • Hormonal changes (menstruation, menopause, pregnancy)
  • Lack of sleep or fatigue
  • Dehydration, fasting, or alcohol intake
  • Bright or flickering lights (screens, neon lights)
  • Sudden weather or altitude changes

 

With or without a headache

Some people experience severe, pulsating headaches after the aura, often on one side of the head, with light or sound sensitivity.
Others have aura without pain. Both are harmless and reversible.

Is a visual aura dangerous?

In most cases, no. A visual aura is benign, though it can be alarming the first time.
Typical symptoms develop gradually, affect both eyes, and last less than an hour.

See a doctor if:

  • It’s your first episode
  • It affects only one eye
  • Symptoms last more than an hour
  • You experience speech problems, weakness, or confusion

When to see a specialist

You should visit an ophthalmologist or neurologist if:

  • Symptoms change or become more frequent
  • They last longer than usual
  • Only one eye is affected
  • The headache is unusually intense or different

An eye and neurological examination can rule out other causes such as vascular or retinal problems.

Treatment and prevention

If pain occurs, standard migraine treatments may help.
In silent migraines, pain relief medication is usually unnecessary.

Prevention tips:

  • Maintain regular, quality sleep
  • Stay hydrated and eat balanced meals
  • Manage stress and practice physical activity
  • Avoid intense light and limit screen time

Frequent cases may benefit from preventive medication or neuromodulation devices.

Don’t panic, but don’t ignore it

Seeing bright patterns or losing part of your vision suddenly can be unsettling, but in most cases it’s a benign visual aura.
Recognizing it and staying calm is key.

At Oftalis, we’re here to take care of your eyes.
📍 Book your appointment at oftalis.com or call +34 972 41 24 13.