Pratyahara is often defined as the conscious withdrawal of energy from the senses. This practice leads to a profound state of relaxation, expanded self-awareness and inner stability. They help us master both the body and the mind.
It takes skill to step back and disengage from the forward momentum of life, long enough to deeply relax and rejuvenate.
Sense withdrawal, pratyahara, rests on the solid foundation of a steady,comfortable posture and a deep, calm breath. Without these two steps, sense withdrawal becomes a battle. With posture and breath regulated, pratyahara comes much more naturally.
Sense withdrawal is a mental function: Withdrawing the senses does not mean just regulating the physical sense organs, such as closing the eyelids or lying physically still. The senses are a mental function, and whenever that mental function is drawn to the objects of the mind field, there is active engagement of the senses. It doesn't really matter whether that mental object is coming from the outside (such as through the eyes), or arising from the memory. It is this internal withdrawal of sensory attention to the mental objects that is the process of pratyahara.
One way to begin to understand Pratyahara on an experiential level is to focus on the familiar posture of Savasana (corpse pose). This pose is done lying on your mat and is the practice of relaxing deeply. The first stage of Savasana involves physiological relaxation. In this stage as you become comfortable there is first an awareness of the muscles gradually relaxing, of the breath slowing and finally of the body completely letting go. While amazing, this first stage is only the beginning of the practice.
In the second stage, you are withdrawing from the external world without completely losing contact with it. This withdrawal is the experience of pratyahara. This experience has been described as feeling like you are at the bottom of a well. You register the sounds that occur around you, for example but those sounds do not create a disturbance in your body or mind. It is this state of non-reaction that is pratyahara. You still register input from your sense organs, but you don't react to that input.