Is it permissible for a niqabi female doctor, whose eyes are uncovered, to wear black contact lenses for the purpose of concealment and to prevent fitna, especially since her eyes are alluring and have caused comments and harassment?

Scholars have differed regarding the obligation of the niqab, and the more preponderant view is that it is obligatory, especially in times of tribulation. If the eyes draw attention, then they should be covered. If it is possible to cover them with something thin, that is preferable. If that is not feasible due to work or study circumstances, then it is permissible to wear black contact lenses if they do not cause harm, because the basic ruling for them is permissibility, and using them for covering and repelling fitna is permissible, and may even be recommended.