This is what I imagine Justin Bieber will look like when he turns 40.

tattooed into the whites of the eyes, not the pupil or iris

Why the fuck would you do this?

some people want to try a different look, there's a facebook page on it though

I have a few friends that done it. It's actually not permanent. If you got it done, you would have to get it redone after a while. They don't hurt to get, but the recovery is meant to be horrible.