Is it necessary to cover the eyes if there is no need to look at the path?

A woman must cover her face from non-mahram men. This is done by letting down a full covering over the face, or by wearing a niqab that covers the face while revealing the eyes. The permissibility of the niqab is indicated by the prohibition for a woman in ihram from wearing it, which implies its permissibility when not in ihram, while being careful not to exaggerate in exposing the eyes or part of the cheeks.