The magnitude, shape, periodicity and frequency of the TLM will depend on many factors such as the type of light source, the electrical mains-supply frequency, the driver or ballast technology[2] and type of light regulation technology applied (e.g. pulse-width modulation).
These TLM properties may vary over time due to aging effects, component failure or end-of-life behavior.
Furthermore, external factors such as incompatibility with dimmers or presence of mains-supply voltage fluctuations (power-line flicker) play a role.
TLMs are also known from non-electrical lighting sources like candle light or they may be experienced while driving along a row of trees lit by the sun or by driving through a tunnel lit by luminaires having a certain spacing.
[4] In additional to mood changes and disturbances, TLM flicker may induce epileptic reactions in susceptible people[3] (photosensitive epilepsy).