I ride with a front light set on blink often. In the daytime. How would that cause a seizure? I can't even tell the light is on unless I put my hand in front of it to check.

I also use one at night, but not as my primary light. I'll run with perhaps the HID on, then a small 100 lumen LED on blink beside it. It's a "be seen" light. I only do that in adverse conditions (fog, heavy rain, snowstorm, etc). I've checked what it looks like to oncoming drivers, and it's not bad at all.