Spontaneous involuntary invisibility

Spontaneous involuntary invisibility (HSII) is a phenomenon in which they become invisible and inaudible to others, even if they are physically present and unaware of their condition.

Even in ancient Indian treatises of a religious and philosophical nature, the Upanishads (scientists refer to the period of the VIII century BC) described supernatural abilities called Siddhas, where one of such yogic Siddhas was human invisibility. Similar ideas are found in later European texts.

Nowadays (in the summer of 1994), Donna Good Higbee learned about this very strange phenomenon that apparently happened to people in the United States. She began to study and popularize it.