Corona currents generated from a person´s head in the vicinity of lightning strikes — Stimulation of phosphenes

Phosphene is a sensory experience which occurs due to the interaction of electric currents generated by an external agent with the visual cortex or retina. Occurrence of phosphenes has been documented in clinical Transcranial Magnetic Stimulation (TMS) studies where electric fields are induced in the brain by the application of time varying magnetic fields. In this paper the possibility of creating phosphenes by the corona currents developing from the head of a person located close to a lightning strike is investigated. The results show that the magnitude of the electric fields induced in the brain by corona currents are comparable to those generated by TMS. This in turn shows that the corona currents generated by long duration lightning flashes could excite phosphenes through their interaction with the visual cortex or retina in a human located in the vicinity of the lightning channel. It is suggested that some of the ball lightning observations reported in the literature could be luminous perceptions caused by the interaction of the corona currents with the visual cortex or retina of a person located in the vicinity of a lightning strike.