Is it permissible to look at female teachers who do not wear the hijab when meeting for a lesson?

It is obligatory to lower one's gaze from female teachers who do not wear the hijab, based on the words of Allah Almighty: "Tell the believing men to lower their gaze and guard their private parts. That is purer for them. Indeed, Allah is Acquainted with what they do" [An-Nur: 30]. One should seek a school free from this objectionable matter.