I have read that in wolf packs, it's all about eye contact, body language, and hierarchy. But recently (I'm sure not recently like a year ago, but you get the point), professionals say it's the wolf's teeth that trigger the fight, not just the eyes. Hmmmm...not really a good example, lets try something else:
Scientists say that most species of monkeys feel challenged and get aggressive when stared into the eyes. Scientists have also noted that some species of monkeys get aggressive when they are showed teeth. Even more intriguing is that some species of monkeys react to both, while others species of monkeys don't react at all!
Personally, I love staring into a bird's eye, or our dog's eye. But if you were to tell to me to look at dog, who is obviously uncomfortable, I wouldn't chance staring into his eyes. I can easily tell when a dog is uneasy, I'm sure most people can; it's what we do with that information that should tell us to stare or not to stare. In past experience, dogs have become more attached to me when I let them approach me with my eyes NOT staring at them. I only make eye contact when dog has become noticeably comfortable with me.
The eyes are the gateway to the heart really.