How we change what others think, feel, believe and do
There are many methods of fixing the attention of the subject. The basic principle is to ask them to do something that requires them to pay attention to something but does not require them to think much.
With the attention fixed, the hypnotist can continue with the process of hypnosis.
When the subject starts to tire, you can suggest they close their eyes.
Hold a finger or pen about a foot from their eyes, level with their forehead and ask them to stare, unblinking at it.
Swing a pocket-watch or other pendulum in front of their eyes and ask them to watch it carefully, without moving their head.
Spin a disc containing spirals in front of them (a modern alternative is to project a computer version on the wall).
Now I want you to watch this carefully. Give all your attention to it, concentrating on it alone. Let your mind go blank except for this. Release all other thoughts as you focus solely on it.
Left to itself, a person's mind will chatter away to itself and drift off in all kinds of directions. Given something to do, it will not so easily be distracted away from the words of the hypnotist.
The conscious mind may also interfere with the process of hypnosis, typically by analyzing what the hypnotist is doing or resisting the process of relaxation. When it is given a concentrated task to perform, the hypnotist may slip past its interference and gain greater access to the unconscious mind.