Point to be Noted: Even though an infant might not respond immediately to the exercises mentioned below, they will learn to do so with time.
Place him on his stomach and place a toy right in front of his eyes, a little distance away. Now place your hands on the soles of his feet and give him a soft push. He will slowly start pushing against your hand and propelling himself forward towards the toy. Place the toy a little away and continue with this activity for sometime. Then let him reach the toy and spend time examining the same.