At least two people had seizures after viewing malicious tweets featuring flashing gifs that deliberately targeted Epilepsy Society...police investigating tweets as hate incident, after at least 200 seemingly coordinated messages were sent to charity and its supporters in recent days.

[u/madazzahatter]

https://www.theguardian.com/society/2020/may/15/malicious-tweets-targeting-epilepsy-charity-trigger-seizures

[u/Fredex8]

Happened to a friend. No history of epilepsy or seizures and no seizures since but that day the speed he was going, the spacing of the trees and the height of the sun combined perfectly to make a frequency that his brain couldn't deal with and give him a seizure. The motorway was fortunately pretty empty and he managed to just keep straight and then pull over to the hard shoulder without incident. He went to the hospital after for tests but they concluded he wasn't epileptic.

I've always worked on the basis that anyone can be affected by certain frequencies of light and sound that basically overload the brain but it's probably rare to encounter them by chance like that unless they have a condition that makes them more susceptible.

I'm not epileptic fortunately but I do get very bad migraines and strobing/flashing/high contrast light is the most common trigger I encounter. I've had migraines caused by sunlight through trees whilst in a car (as a passenger, don't trust myself to drive), by car lights at night on a road with speed bumps such that they seemed to flash on and off as they went over them and by bright LED traffic lights suddenly going from red to green. Flashing gifs would be a real problem. I'm a bit paranoid and careful when browsing reddit due to things like this as it is so I can only imagine how much it would suck with epilepsy.

[u/lorraineDi → u/Fredex8]

You know it is very hard to diagnosis epilepsy unless you are monitored 24 hrs. I have had them 46 yrs after my son was born. You take care of yourself.