与别人说话时看着对方的眼睛是他的习惯。用英语怎么说？

It is his habit to look people's eyes derictly while they are talking

he has the habit of looking directly in the eyes of those he talks to .
i too have this habit.

It is his habit that watching eyes whose is talking with him.

His habit is when talking with others look into the other person's eyes.

he has the habit of watching others' eyes while talking .