Modern use of flickering light has the advantage of precise and controllable fast reaction LED’s. But the history of the fascination with flicker induced visual hallucinations is much older than that.
Stories of Shamans using a leaf waved in front of the sun and potentially even historical figures famous for their creative thinking using the sun in a similar way go back many hundreds if not thousands of years.
With the advent of EEG brainwave measuring devices and modern lighting came a new look at this effect of patterns and colour produced in the minds eye behind closed eyelids.
Interestingly it was the use of flickering light with EEG to test people for potential epilepsy seizure risk that was one of the main reasons for renewed interest in light induced psychedelic experiences.
And of course with the criminalisation of substances like LSD, the potential to have a similar enlightening experience with just light became more attractive too.
This interest led to stroboscopes and dream machines and more recently photic light based brainwave entrainment devices.