Photopsia describes brief flashes of light or flickering sensations in the visual field that are not caused by external light sources. It is a symptom rather than a diagnosis and can arise from changes in the eye or visual pathways.
Causes
Common ocular causes include traction on the retina during posterior vitreous detachment or retinal tears, as well as inflammation or vascular disturbances. Photopsia can also occur as part of migraine aura, usually accompanied by other visual patterns such as zigzag lines or shimmering shapes.
- Flashes often appear in the peripheral vision and last seconds
- New onset flashes with floaters can indicate retinal pathology
- Migraine-related photopsia typically affects both eyes and evolves over minutes
- Neurological causes may be associated with additional symptoms such as weakness or speech disturbance
Assessment
Any sudden increase in flashes, especially when accompanied by a shower of floaters or a shadow over vision, requires prompt eye examination to exclude retinal tear or detachment. History and examination help differentiate ocular from neurological origins.
- Dilated retinal assessment is essential when retinal traction is suspected
- Neuroimaging may be indicated if neurological signs are present
- Documenting frequency and triggers can clarify patterns over time
- Management is directed at the underlying cause once identified
