When you are giving him a visual presentation using books, charts, graphs and so on. Research shows that of the information relayed to a person's brain, 87 per cent comes via the eyes, 9 percent via the ears, and 4 per cent via the other senses.
To maintain maximum control of his gaze, use a pen or pointer to point to the visual aid and at the same time verbalise what he sees. Next, lift the pen from the visual aid and hold it between his eyes and your own eyes. This has the magnetic effect of lifting his head so that he is looking at your eyes
and now he sees and hears what you are saying, thus achieving maximum absorption of your message.