One rule of traditional Japanese etiquette that contrasts with etiquette in the United States is how to use the eyes to show respect and attention. Where a Japanese might look down when showing respect, to an American this is a sign of lack of interest or even rudeness.
Having said this, however, it is not necessary to maintain eye contact one hundred percent of the time. In America, people feel uncomfortable if they are “stared at” constantly, so it is important to maintain a balance. A good rule is that the person speaking will look at the listener perhaps sixty percent of the time in order to avoid seeming domineering, while the listener will look at the speaker seventy–five percent of the time to show interest in what the speaker is saying. It is acceptable for both people to glance to one side occasionally, but one should not avert one’s gaze too long.