Rabbi Elchonon Wassermen zt”l would never stare at someone in the face(when talking), this is based on Igros Ramban, in which he adjures his son, not to look at someone whilst they are talking as its not humble.
It also says ‘k’mayim panim al hapanim (Mishlie)as water reflects so does the face. Therefore it is good to look at people whilst talking to them.
Perhaps Ramban and Rabbi Elchonon Wassermen were Litvaks who don’t look at people when they speak.
Chassidishe Rebba (who Kabbalistaically face read people) do look at people, also fuffiling the verse ‘your eyes should see your teacher (Isaiah)-in which the Talmud adjures people to look at the Rebba when they speak.