Now that I have managed to get the head mostly assembled I decided to use an RC Servo tester running at 6 Volts to test the eye movement. I have tested both the up and down movement as well as left and right.
I still have some fitment to do as there is some rubbing going on, but that will be fixed before the final assembly.
NOTE: I am not the creator of this robot. The InMoov Robot was created by Gael Langevin, you can read more about it here: http://inmoov.fr/.