flashing led lights...problem?

[grizedale]

why are there no reports of epileptic seizures being brought on by people looking at LED police sirens which flash on/off at 40ms/10ms repeatedly.?

There are loads of reports of people getting epilepsy from viewing fluorescent bulbs due to the fluctuation of the light due to the the mains rectifier output.

So why no reports of epilepsy with LED lights which flash very quickly?

 

[tpetar]

Epilepsy attack is not linked with led lights its linked with RED light or any strong color based on red. If this red color blinking or have some fast changes this can cause epilepsy attack at person which even didnt know that have epilepsy. If you have strong super hell red leds this can cause this. Must be fast changing red colors.

 

[grizedale]

there is just as much red in a white LED as there is in a white fluorescent lamp, so that cant be right

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there is just as much red in a white LED as there is in a white fluorescent lamp, so that cant be right

 

[godfreyl]

Interesting question!

Apparently epileptic seizures can be triggered by flashing lights of any color with a frequency between about 10Hz to 20Hz, so police lights are designed to flash at a lower frequency to minimize the risk.

Your 40ms/10ms figures contradict that though, giving a frequency of 20Hz. Are you sure those times are correct?

 

[grizedale]

hi

yes i promise you, i swear on my life.........here is a typical flash sequence for the left side of a light bar

44ms on
10ms off
44ms on
10ms off
44ms on
298ms off

then repeat


....this is happening on the right side too but shifted in phase.

well in the danger region for seizures, so why no complaints?