HELP! eyes dont move properly with head?!

[Crumbledough]

i crated a minecraft character in blender with a face rig and everything works fine apart from the eyes. when i move/rotate the head the eyes follow the bone at a slower speed that the rest of the head for example if i moved the head back so that my character is facing the up the eyes would be sticking out forwards because it hasnt moved as fast as the rest of the head. the eyes are the same mesh as the head so i cant parent it and weight paint doesn't work at all and i really dont know what to do?! can anyone help?

and this is my first time posting and dont know if this has been asked or is on the wrong place so sorry in advance