Epilepsy warning

This is the first time I've seen a DVD with a warning that flasthing lights may aggravate epileptic conditions. Presumably this is because of the lasers used in the concert, a practice that seems to have been largely discontinued:

This film contains flashing lights which may not be suitable for photosensitive epilepsy.
Does anyone know the risks to epileptics in watching this film, or is this largely protection from the legal department?

Regardless, I think this is an amazing concert and a nearly-perfect film. 9/10 stars from me.


For about 3 percent of people with epilepsy, exposure to flashing lights at certain intensities or to certain visual patterns can trigger seizures. This condition is known as photosensitive epilepsy.

Photosensitive epilepsy is more common in children and adolescents, especially those with generalized epilepsy, and a type known as juvenile myoclonic epilepsy. It becomes less frequent with age, with relatively few cases in the mid twenties. Many people are unaware that they are sensitive to flickering lights or to certain kinds of patterns until they have a seizure.

Not all televisions, video games, computer monitors, and strobe lights trigger seizures, however. Even in predisposed individuals, many factors must combine to trigger the photosensitive reaction.

Examples include:

Frequency of the flash (that is, how quickly the light is flashing)
Contrast with background lighting
Distance between the viewer and the light source
Wavelength of the light
Whether a person’s eyes are open or closed

The frequency or speed of flashing light that is most likely to cause seizures varies from person to person. Generally, flashing lights most likely to trigger seizures are between the frequency of 5 to 30 flashes per second (Hertz).

The likelihood of such conditions combining to trigger a seizure is small.

I run a bunch of strobes at my Halloween displays over the years
and never had anybody fall over on the lawn.

You're more likely to suffer a migraine listening to Lindas backing vocals.


Pffft, my suspension of disbelief has higher standards than that.