I do too, never had a headache with it. The first time it happened to me I was in my early forties. I was all alone at an overnight shift at work, and wondered if pulsating rainbows that were impossible to read through were my future. That time it only lasted about 25 minutes, and a quick Google let me know what was going on.
I still get them about once every two weeks or so. I don’t really have a choice when they start showing up, and will tell my team I will be useless for anything that requires reading for the next 35-45 minutes.
I also got them for a while. They began after my neighbour painted their house a particular shade of yellow, and the sun reflected off it right into my eyes (it happened to be precisely where I sat at my computer desk). Somehow that particular combination of frequency of light and angle of the sun triggered them. Since moving away they have ended.
I just had my fourth one, and I detailed over in the MMP more about them. I’m posting here to chime in that light seems to trigger them, especially the bright white light of a hazy summer day or the overly bright lighting inside a Target.
Every once in a while, I get this effect where I’m seeing stars — do you remember The Green Mile where John Coffey spits out those things that were someone’s affliction? It’s like that, only they’re see-through.
I watched the Netflix documentary The Idaho Murders: College Nightmare last week, and the killer claimed to have visual snow syndrome that somehow caused him to be detached from society.