I had a large supermarket near me that had advertising in store that was those very fast spinning led fan things. They spin very fast to make an image with the LEDs.

I had to avoid that shop for several months before I peered through the outside and saw they was gone. I assume they got complaints.

Just ask autists, they'll tell you.

Walking down some of the more visually busy aisles I tend to get hit by that. I suddenly feel a combination of very tired, mild headache and the sensation you get when you've got the sun in your face. It goes away once I leave the horrible place. I can't believe some people have to work there all day every day.