If you stretch out a hand to one side of you, you might find the point on the edge of your vision where you only see that hand when you waggle the fingers. Another kind of vision, 'peripheral' vision, takes in the whole panorama of what's happening in front of us and around us. It uses different light receptors in the retina and different neural pathways in the brain. As you experienced your peripheral vision, you might have noticed certain physiological changes - perhaps a shift in your breathing from higher to lower in the chest, a relaxation of face and jaw muscles, and maybe later your hands became warm. If you normally have an internal dialogue going on, you might have noticed it was quieter than usual, or stopped altogether.
Peripheral vision is known and used in many older cultures as a tool for achieving useful states.
In martial arts, peripheral vision allows you to be aware of any movement an opponent makes with his hands, for example, while keeping the rest of him in view. You can see how useful that would be if there was more than one person coming at you at once. If you are a therapist and would like to use peripheral vision to help clients, you may want to read an article on peripheral vision which I have written for the National Council for Hypnotherapy Journal.