The amount of detail in the eye is impressive, but it becomes almost a little bit creepy when portrayed on a chibi. I'd either simplify your eyes a bit, or... and this is going to sound like a weird solution, but I'm only going by what I've seen... maybe make them much bigger.
Why?... Well, I guess I'm thinking that the eye looks too lifelike, so making it more "deformed" like the rest of the image would make it mesh better.
But hey, I'm untrained, so it's okay to ignore me, eh?