Too much white in the eyeballs. That will be the next frontier, no doubt.
They already have some who specialize in tattooing eyes. I saw it on the discovery channel that they can tattoo the whites with either full coloring or by inserting objects just under the clear part.
They even can tattoo in some glow in the dark ink to make your eyes glow under a black light.
I’ve got 3 tattoos and they really don’t hurt much. They feel like someone scraping your skin a bit and it feels like a mild sunburn for about a day or two.
But I cant imagine having anyone doing it to my eyes. That would be going too far.