Is it permissible to widen the openings of the niqab to show the eyebrows, part of the forehead, cheeks, and nose, or is it obligatory to restrict it to showing only the eyes, with the niqab tightened between them without any beautification of the eyes?

Covering a woman's face from non-mahram men is obligatory, and there is no harm in her showing her eyes to the extent that she can see, provided that the niqab does not reveal the eyebrows, forehead, or cheeks, and that there is no adornment in them, such as kohl.