The delicacy of this method demands striping your collocutor of any glasses or other objects that may be in front of his eyes and then disabling the blinking function by holding his eyelids.
Or, in the case you mentioned, it’s even simplier. If he’s lying the eyeballs will turn right and probably the whole body will unconcousely follow it in the same direction, just the body movement will be hardly visible. The special glasses are actualy helping because they react to it with the visible movement to the left.