As far as I know, the first person to suggest that a computer display could be hacked to induce seizures in epileptics is science fiction writer John Varley. In his award-winning 1984 story Press Enter, a sinister artificially intelligent computer system does just that:
"... then the screen started to flicker. I stared at it for a while. It seemed to me that there was an image trying to form on the screen. Something three-dimensional. Just as I was starting to get a picture of it I happened to glance at Lisa, and she was looking at me. Her face was flickering. She came to me and put her hands over my eyes.
'Victor, you shouldn't look at that...'" (Read more about Display-Induced Epileptic Seizure)
Via Hackers Assault Epilepsy Patients via Computer.
(This Science Fiction in the News story used with permission of Technovelgy.com - where science meets fiction)