Ok what I did was make your eye group into a UV texture. Basically I split the window, used the UV/image editor, and while in edit mode I hit U > project from view (bounds)
This made the eyes unwrap onto that eye image you had selected. I unselected the points and then hit L on the left side of the points (this is all in the UV/image window) to select the points on the left (make sure the mouse is near those points) I think mirrored those points M > mirror X. I then aligned the points to match that on the right, and placed them how I wanted over the eye
back in edit mode and in the shading menu, I went to the Material button (big red sphere next to the tiger skin) and under the MAP INPUT tab I selected UV, and then changed the way the image was layed out to flat, and not cubed. If you have any other questions feel free to ask!
voltorb.blend (218 KB)