Flashes of Light (Photopsia) — Retinal Emergency Paris

Flashes of light, flashes or photopsia — white or coloured flashes perceived even with eyes closed or in the dark — can be a sign of traction on or a tear of the retina. When sudden, repeated or accompanied by other symptoms, they warrant urgent ophthalmic consultation.

What are flashes of light (photopsia)?

Flashes of light, also called photopsia, are light perceptions that do not correspond to any external light source. They appear as white flashes, arcs of light or sparks, most often in the peripheral visual field.

They occur when the retina is mechanically stimulated — for example when the vitreous body exerts traction on it during posterior vitreous detachment.

Are flashes of light always serious?

Not necessarily. Isolated photopsia, particularly in young adults, can be caused by migraine with aura (visual migraine), often presenting as coloured zigzag lines in both eyes lasting 20-30 minutes. This is benign and requires no urgent action.

Conversely, flashes that are new, unilateral, repeated, associated with floaters or a dark curtain strongly suggest vitreoretinal traction or a retinal tear. In this context, they constitute a true ophthalmic emergency.

Flashes of light and posterior vitreous detachment

The most common cause of sudden photopsia is posterior vitreous detachment (PVD): the vitreous gel separates from the retina and, by pulling on it, mechanically stimulates the photoreceptors which interpret this stimulus as light. This traction can tear the retina in about 10-15% of cases.

What to do in case of sudden flashes of light?

Any new onset of flashes of light, even without other symptoms, requires rapid fundus examination by a retina specialist. Only a dilated fundus examination can rule out a retinal tear or detachment. If flashes are accompanied by a shower of floaters or a dark curtain, seek emergency care immediately — do not wait.