"Short eyes" is something of an old-fashioned term that isn't much used in prisons anymore--at least not prisons in La. It's like the terms "Bull" or "Turn-key" for guard. Authentic but historical. Nowadays pedophiles are referred to as "Baby-rapers" or "Chesters" (as in "Chester the Molester").
There are a number of reasons pedophiles are abused in prison. Part of it is, yes, many of the inmates are fathers themselves. But a man who has _murdered_ children, even his own, doesn't come in for near as much abuse. So it's hard to credit inmates for much nobility or righteous outrage in going after the baby rapers. I think what it really comes from is a common human behavior--kicking the abuse downhill. As in, even murderers have found someone to point the finger at and express indignation. Of course it's all BS. I heard a baby raper once tell a murderer "at least my victim is still alive" and you know what? He was right.
Myself, I would gladly take the life of any person who harmed or killed my child, so I can't say that I have sympathy for either of them. But, if put in the position of having to make a horrible choice, I would always choose to have my child _alive_. I think most people would say the same.
The worst possible thing you can do to another, and all those who love that person, is remove them from the world. It's a hole that can never be filled, a wound that never heals. Don't ever think that _anyone_, even baby rapers, are worse.