"The 'deva-eye' exists no more for the majority of mankind. The third eye is dead, and acts no longer; but it has left behind a witness to its existence. This witness is now the pineal gland."
That's a quote from Theosophy founder H. P. Blavatsky and while it's firmly rooted in the spiritual world, it does manage to sum up humanity's ongoing relationship with the notion of a buried third eye, our very real pineal gland and the primeval origins of sight.
In this episode of Stuff to Blow Your mind, we discuss the human pineal gland. So we'll discuss how this eye-like structure inside our heads transduces sense signals about the world outside our body into hormonal signals.