Ajna (Sanskrit: आज्ञा, IAST: Ājñā, English: "command") or third-eye Chakra is the sixth primary chakra of the seven centres of spiritual power in the human body according to Hindu tradition. It is believed that awakening this chakra gives super powers of intuition.
The Ajna chakra is positioned in the pituitary gland, directly behind the center of the forehead. Its ksehtram, or superficial activation site, is between the eyebrows at the position of the "third eye." The location makes it a sacred spot where Hindus apply vermilion to show respect.
Ajna is represented by the color indigo. It is also known as the sixth chakra, or third eye chakra. Through this chakra, we view all the depths of chakra connectivity. In indigo pools of depth and contemplation we see more clearly how energy runs together. Indigo is an oceanic orifice - always present - just waiting for us to dive in to discover the behavior and rhythms of energy itself. When we swim round its ripples, we see all energy is interrelated, each nuance a partner, each ringlet interlinking depth and texture to the story of our existence. It's like we've returned to our red chakra roots, come up through ourselves by way of the chakra spine only to meet ourselves again with new understanding. 
Bija or Seed mantra
The seed syllable is Aum, or "Pranava Om," the supreme sound.
Ajna has two white petals, said to represent the psychic channels (nadis) Ida and Pingala, which meet the central Sushumna nadi before rising to the Crown Chakra Sahasrara. The letter "Ham" is written in white on the left petal and represents Shiva. "Ksham", written in white on the right petal, represents Shakti. These two petals also represent the manifest and the un-manifest mind, and are sometimes said to represent the pineal and pituitary glands.
Ajna translates as "command", and is considered the eye of intuition and intellect. When something is seen in the mind's eye, or in a dream, it is being seen by Ajna. It is a bridge that links gurus with disciples, allowing mind communication to occur between two people. The sense organ and action organ associated with Ajna is the mind.
As Hindus believe that spiritual energy from the environment enters their body through this gateway, they take great care to protect it with spiritually positive protecting forces. The various religious marks on the foreheads of men and women belonging to the Hindu faith (like holy ash, namam, vermilion etc.) are the blessed spiritual prasadam of their respective forms of the Hindu gods.
Meditation upon Ajna supposedly grants siddhis, or occult powers, to quickly enter another body at will and to become omniscient. He realizes unity with Brahman; and he has the ability to create, preserve, and destroy the three worlds.
Directly above Ajna is a minor chakra known as Manas, or mind. It possesses six petals, one for each of the five senses and one for sleep. These petals are normally white, but assume the color of the senses when activated by them, and they are black during sleep. This chakra's function is sending sense perceptions to the higher chakras.
Association with the body
Ajna is associated with the third eye on the forehead. It is also sometimes associated with the pineal gland, which regulates the circadian rhythm, and is related to an actual light-sensitive 'third eye' (Parietal eye) found in some lizards, amphibians, and fish. It is also sometimes associated with the pituitary gland, which is major endocrine glands.
In kundalini yoga, the practices said to stimulate the Ajna chakra include: Trataka (steady gazing), Shambhavi Mudra (gazing at the space between the eyebrows), and some forms of Pranayama (breath exercises).
Comparisons with other systems
In Tibetan Buddhism, this chakra is at the end of the central channel, which runs up the body to the top of the head, and then over and down, terminating at the forehead. The two side channels continue inwards towards the two nostrils and end there. This center is frequently depicted in artwork as the third eye and is used in various meditations.
The Ajna in human design is a part of the mind where you find Thoughts, Answers, Opinions, Insights, Ideas, and Conceptualizing, as well as the not self thinking of pretending to be certain when anything can happen. The Ajna is where the personality crystal is located after birth. When you are born your spirit enters into your vehicle and sits in the Ajna. It is here that one finds them self internalizing thoughts and ideas. The Ajna is not a motor center meaning it cannot actively operate the design.
There is also a forehead center above the third eye, which corresponds to the position of Manas, one of the ten chakras in the Mahayoga tantra traditions.
In Qigong, the highest Dantian is located at this position. This is one of three furnaces that converts the different sorts of energy in the body. In this Dantian, the spiritual shen energy is converted into wuji, the infinite space of void.
According to the Kabbalah, there are two sephiroth located on the sixth level, associated with the left and right parts of the face. They are called Chokmah (wisdom), and Binah (understanding); it is at these points that the two side pillars of mercy and severity terminate, while the central pillar carries on rising to kether, the crown.
- In Tantra: Ajita-Patra, Ajna, Ajna-Pura, Ajna-Puri, Ajnamhuja, Ajnapankaja, Bhru-Madhya, Bhru-Madhya-Chakra, Bhru-Madhyaga-Padma, Bhru-Mandala, Bhru-Mula, Bhru-Saroruha, Dwidala, Dwidala-Kamala, Dwidalambuja, Dwipatra, Jnana-Padma, Netra-Padma, Netra-Patra, Shiva-Padma, and Triweni-Kamala
- In the Vedas, Upanishads: Ajna, Baindawa-Sthana, Bhru Chakra, Bhruyugamadhyabila, and Dwidala
- In the Puranas: Ajna, Dwidala, and Trirasna
- Swami Satyananda Saraswati. Kundalini Tantra
- 1 page 268, Kundalini Yoga for the West, Swami Sivananda Radha, Copyright 1978, Shambala Publications, Inc.
- "Third Eye Chakra". ASIS Massage. Retrieved 25 July 2013.
- Geshe Kelsang Gyatso. Tantric Grounds and Paths
- Andy James. The Spiritual Legacy of Shaolin Temple
- Dion Fortune. The Mystical Qabalah