Problem solved!
I made a separate method in the model class, that renders the pupil separately.
This is my render code:
EntityPlayer ep = Minecraft.getMinecraft().thePlayer;
float eyeX = Math.max(Math.min((float) ((ac1_rot == 0 ? tee.xCoord : (ac1_rot == 90 ? -tee.zCoord - 1.0F : (ac1_rot == 180 ? -tee.xCoord - 1.0F : tee.zCoord))) + 0.5F - (ac1_rot == 0 ? ep.posX : (ac1_rot == 90 ? -ep.posZ : (ac1_rot == 180 ? -ep.posX : ep.posZ)))), 1.0F), -1.0F) * 1.8F;
float eyeY = Math.max(Math.min((float) ((tee.yCoord) + 0.5F - (ep.posY)), 1.0F), -1.0F) * 1.8F;
this.model.renderModel(0.0625F);
GL11.glTranslatef(eyeX / 12.0F, eyeY / 12.0F, 0.0F);
this.model.renderPupil(0.0625F);
Now, all the eyes are staring at me