The third eye is a mystical and esoteric concept referring in part to the brow chakra in certain Eastern and Western spiritual traditions. It is also spoken of as the gate that leads within to inner realms and spaces of higher consciousness.
In New Age spirituality, the third eye may alternately symbolize a state of enlightenment or the evocation of mental images having deeply personal spiritual or psychological significance. The third eye is often associated with visions, clairvoyance, precognition, and out-of-body experiences.
In Hinduism and Buddhism, the third eye is a symbol of enlightenment. In the Indian tradition, it is referred to as the gyananakashu, the eye of knowledge, which is the seat of the ‘teacher inside’ or antar-guru. The third eye is commonly denoted in Indian and East Asian iconography with a dot or mark on the forehead of deities or enlightened beings, such as Shiva, the Buddha, or any number of yogis, sages and bodhisattvas. This symbol is called the “Eye of Wisdom”, or, in Buddhism, the urna. In Hinduism, it is believed that the opening of Shiva’s third eye causes the eventual destruction of the physical universe.
According to Max Heindel’s Rosicrucian writings, the third eye is localized in the pituitary body and the pineal gland. It was said that in the far past, when man was in touch with the inner worlds, these organs were his means of ingress thereto, and they will again serve that purpose at a later stage. According to this view, they were connected with the involuntary or sympathetic nervous system, and to regain contact with the inner worlds it is necessary to establish the connection of the pineal gland and the pituitary body with the cerebrospinal nervous system. It was said that when that is accomplished, man will again possess the faculty of perception in the higher worlds, but on a grander scale than it was in the distant past, because it will be in connection with the voluntary nervous system and therefore under the control of his will.
Some writers and researchers, including H. P. Blavatsky and Rick Strassman, have suggested that the third eye is in fact the partially dormant pineal gland, which resides between the two hemispheres of the brain. The pineal gland is said to secrete dimethyltryptamine, which induces dreams, near-death experiences, meditation, or hallucinations. Various types of lower vertebrates, such as reptiles and amphibians, can actually sense light via a third parietal eye, a structure associated with the pineal gland, which serves to regulate their circadian rhythms.