"But I'd hit the point in my life where I felt I had zero control and was about to lose the one thing in my life that meant the most which was my family, so I was prepared to try anything."

Sergeant Butler demonstrates the computer scenario which was used to help him.

On a computer screen I can see the same image projected onto Sergeant Butler's visor.

He is in the front seat of a Humvee armed vehicle patrolling the streets of Iraq; each time he turns his head, the viewpoint on the screen changes.