Magnetic stimulation thresholds for the perception of magnetophosphenes – a numerical study

Magnetophosphenes are luminous sparks perceived by persons exposed to a magnetic field of moderate amplitude and variable over time at low frequency (i.e., 10-40 mT and up to 30 kHz), when a certain threshold of stimulation of the sensitive retinal tissue is exceeded. The effects of exposure to the variable magnetic field are explained by electromagnetic induction; in this case, retinal eddy currents are generated. Our paper identifies and discusses the limits of sensitivity under such exposure conditions, reflected by normative documents; then compares them with experimental results from the specialized literature and presents an attempt to correlate data from these experiments with results of original numerical analysis. The main goal is to find reasonable data comparable to the perception thresholds of magnetophosphenes, in an extended frequency range, with utility in medical applications such as neuromodulation or retinal integrity assessment.