Certain patterns of light — flashing bright lights at particular frequencies — synchronize cells within the visual cortex. If the neurons then fire through their networks at too high a level, they can recruit other neurons into a hyper-synchronous discharge. That's what happens in the brain during a seizure.

Why do bright flashing lights cause seizures?

Images flash very quickly and generally this is too quickly to trigger a seizure in people with photosensitive epilepsy. However, the field of view is large and so more of the eye is stimulated. This means that more of the brain may be affected and this may trigger a seizure.

Why do Strobe lights make me feel weird?

Flicker vertigo, sometimes called the Bucha effect, is "an imbalance in brain-cell activity caused by exposure to low-frequency flickering (or flashing) of a relatively bright light." It is a disorientation-, vertigo-, and nausea-inducing effect of a strobe light flashing at 1 Hz to 20 Hz, approximately the frequency ...