The two normal eyes are capable of functioning only on the physical plane. The third eye or the divine eye, however, functions on the subtle mental planes or even on transcendental levels. The objects perceived by the third eye are far more subtle than those seen in the gross external world. They present themselves as thought forms or images independently and are directly perceived without the need of the senses or external objects.
Human beings are endowed with the five sense-organs including the eyes. No external object can be seen unless the eyes present their images to the mind, and the eyes have to remain open to perform their task. But not so with the third eye. It needs no help from the sense organs, nor does it have to form any image on the so-called screen of the mind, the chitta. Therefore, in order to achieve the third eye for attaining spiritual insight, one must first close any and every access to sense perception.
The withdrawal of the senses from their objects is known in yogic terminology as pratyahara. This is the first step for the seeker of truth, in preparation for the next stage, namely Meditation. Practice of meditation, sadhana, performed in the prescribed manner, animates the dormant third eye and reveals to the Self within the vast and illimitable vistas of creation, beginning with the unknown and unmanifest, the mul prakriti or nature in its static state, avyakta.
This formless and attributeless mul prakriti represents the universal primordial energy, shakti, in its potential form. The act of creation is achieved by the changeover of this potential energy into its kinetic form, which sets uo the matter in a flux of perpetual motion. Matter and energy, it will be noted, are convertible entities, regulated by the formula E=mc2. E is energy, m is mass and c is speed of light. The visible universe (vyakt) is merely a display of the energy (adi shakti) before the conscious Self or jivatma