Looking any bear in the eye works very well.....as long as the looking is done through the scope of a high powered rifle.

There was an erie video a few years ago about a blackie stalking a guy for miles. He filmed it all and it was a miracle it never attacked.
I have killed one black bear. Amazing animals and when skinning him, the claws and muscles were awe inspiring. Not something I would want to go up against with pepper, bells or a sharp stick!