I completely disagree with lilmali. To be honest, I like simple heads alot more than other heads.
About your head, it's pretty cool, but even if I like simple heads, it could use more details, especialy in the back. I love the glow in the eyes though. But the mouth (if you intended to make that a mouth) didn't realy catch my attention.
Oh and the shadow in the front looks better than in the back.