What is the cause and treatment of zig zag lights (photopsia) affecting both eyes whether they are open or closed?

Zig Zag Lights in Both Eyes: Migraine Aura

This is almost certainly migraine aura (also called "scintillating scotoma" or "fortification spectra"), which characteristically presents as zig-zag or shimmering lights visible with eyes open or closed, affecting both eyes simultaneously, and typically lasting 10-30 minutes before resolving. 1, 2

Why This is Migraine Aura

The key diagnostic features that point to migraine aura include:

• Bilateral and simultaneous presentation - Unlike posterior vitreous detachment or retinal problems which are typically unilateral, migraine aura affects both eyes at once because it originates in the visual cortex of the brain, not the eyes themselves 2

• Visible with eyes closed - This is pathognomonic for a neurological (cortical) origin rather than an ocular problem. Retinal or vitreous causes of photopsia disappear when eyes are closed 1, 2

• Zig-zag morphology - The classic "fortification" pattern (zig-zag, shimmering, or geometric patterns) is highly specific for migraine aura 1, 2

• Self-limited duration - Migraine aura typically lasts 10-30 minutes, whereas retinal causes tend to be quick flashes or more persistent 2

Two Clinical Variants

Migraine with aura - The visual symptoms are followed by a headache (typically unilateral, throbbing) within 60 minutes 1

Migraine aura without headache (also called "acephalgic migraine" or "ophthalmic migraine") - The visual symptoms occur without subsequent headache, which is particularly common in older adults 1, 2

Critical Differential Diagnoses to Rule Out

While migraine aura is most likely, you must exclude sight-threatening conditions:

Posterior Vitreous Detachment (PVD)

• Unilateral quick white/silver flashes in temporal visual field 2
• Associated with new floaters (85% of cases) 2
• Worse in dark environments (90%) 2
• Triggered by head/eye movements (60%) 2
• Does not occur with eyes closed 1

Retinal Tear or Detachment

• Similar to PVD but may have more central or non-temporal location (40% in detachment) 2
• Progressive visual field loss (curtain or shadow) indicates detachment 1
• Requires urgent ophthalmology referral within 24 hours 1

Vertebrobasilar Insufficiency

• Bilateral photopsias but associated with neurological symptoms (vertigo, diplopia, ataxia, weakness, numbness) 2
• More common in elderly with vascular risk factors 2

Treatment Approach

For Acute Episode

• Reassurance - The episode will resolve spontaneously within 10-30 minutes 1
• Rest in a quiet, dark environment 1
• No specific acute treatment is required for isolated visual aura 1

For Recurrent Episodes

Identify and avoid triggers:

• Stress, sleep deprivation, certain foods (aged cheese, chocolate, alcohol), caffeine withdrawal, bright lights, hormonal changes 1

Prophylactic medication (if episodes are frequent or disabling):

• Consider referral to neurology for preventive therapy if episodes occur more than 4 times per month or significantly impact quality of life 1
• Common prophylactic agents include beta-blockers, calcium channel blockers, or anticonvulsants (prescribed by neurology) 1

When Migraine Progresses to Headache

• NSAIDs or acetaminophen for mild headaches 1
• Triptans for moderate-to-severe migraine headaches (if no contraindications) 1

Red Flags Requiring Urgent Evaluation

Seek immediate ophthalmology evaluation if:

• New onset floaters accompany the flashes 1, 2
• Flashes are unilateral only 2
• Visual field defect persists after the episode 1
• Flashes persist beyond 30-60 minutes 1, 2

Seek emergency neurological evaluation if:

• First episode after age 50 (higher risk of stroke mimics) 1
• Associated with weakness, numbness, speech difficulty, or severe headache (worst of life) 2
• Symptoms don't follow typical migraine aura pattern 1

Common Pitfalls to Avoid

• Don't assume all bilateral photopsias are benign - While migraine is most common, bilateral simultaneous flashes can rarely indicate vertebrobasilar insufficiency or occipital lobe pathology 2

• Don't miss retinal pathology - If there's any uncertainty about laterality or if floaters are present, dilated fundus examination is mandatory to exclude retinal tear or detachment 1, 2

• Don't overlook medication causes - Certain drugs (digitalis, topiramate) can cause photopsias 2