Bucha effect

The Bucha effect is a seizure-inducing effect of light flashing in high frequency, similar to epilepsy but without being restricted to a small fraction of the population.

Named after a Dr. Bucha who discovered it in the 1950s when called upon to investigate a series of similar and unexplained helicopter crashes. The pilots who had survived had felt fine until they suddenly became dizzy and confused, losing control of their aircraft. Dr. Bucha found that when the blades happened to maintain a certain rotational rate for sufficient time, wherin the resultant strobing of sunlight closely matched human brainwave frequencies, it could induce symptoms similar to epilepsy.

The Bucha effect has been considered as the priciple for various forms of "non-lethal weapon".