Seki
There is a possibility for stones to be alive without eyes. This situations happens when two groups of otherwise dead stones face each other without being able to achieve capture.
The figure on the right shows one of the most simple seki. The black and white stones in contact with the circled points don't have any eyes and may seem dead. However, if Black tries to capture white, he needs to fill one of the circled point, which will only leads to its own capture by white. The same applies to White, who cannot fill black liberties without being captured first.
Since none of the players can kill the other, the situation is considered settled. The black and white stones are said to be alive in seki.
Read more about this topic: Life And Death