Throughout Eastern and Western religious traditions, the third eye is thought to be the gateway to the "inner eye." People who have developed their third eye (the anja chakra) are known as "seers."
Hinduism and Buddhism use the third eye as a symbolism of enlightenment. In Indian tradition, it is known as the "eye of knowledge." Hindus place the red dot, or "tilak," between the eyebrows as a representation of the third eye.
But what is the all-seeing eye and does it actually work?
The third eye is actually connected to a part of the brain known scientifically as the pineal gland. The pineal gland is located in the middle of the brain and controls melatonin, which makes you sleep. It regulates sleep cycles in most vertebrates. Perhaps the pineal gland is connected to the third eye historically because it is associated with dreaming.
Scientific research supports that the third eye was once our first eye. The pineal gland is made out of cells that have similar features to the rod cells (which detect light) found in retinas in the eye. The third eye may have been a sight organ before the current set of eyes which many animals today possess. The pineal gland is located in the part of the brain which controls consciousness and the body's sensory and motor functions.
But is the pineal gland a portal to higher dimensions?
Interestingly enough, the pineal gland is linked to the production of DMT, which causes psychedelic experiences. DMT is also released in near-death experiences. This may be the third eye's connection to the spiritual world.
The pineal gland is thought to have controlled "remote viewing" and psychic abilities. This, theoretically, would be being able to see into another room or place anywhere on Earth remotely (without actually being in that room). We are told that these abilities are not real; yet, the American and Soviet governments have tested remote viewing.
Some claim that the secrecy behind shrouding the truth of the third eye was caused by the Illuminati, to create a New World Order.
We have yet to scientifically discover Heaven, Nirvana or the after-life. However, the third eye is surely at least the gateway to the inner eye. It controls our senses, and thus makes life seem "fuller" when it is more active. And it controls sleep cycles, leading us into the unconscious. It is definitely the portal between consciousness and unconsciousness.