Then his eye is fathomless blackness.

But there is the dark eye which glances with a certain fire, and has no depth.

There is a keen quick vision which watches, which beholds, but which never yields to the object outside: as a cat watching its prey.

The dark glancing look which knows the _strangeness_, the danger of its object, the need to overcome the object.

The eye which is not wide open to study, to _learn_, but which powerfully, proudly or cautiously glances, and knows the terror or the pure desirability of _strangeness_ in the object it beholds.