It depends on the face shape of the girl or whether she choose the right style glasses for her face.Some girls look uglier with glasses but some are sexier. The answer for this one can't be unified.
It is really hard to say.If a boy likes a girl,it should not matter whether she wears glasses or not.But it does make a difference in their look with glasses or not.Some girls look quite elegant and sexy with them.
Everyone including boys likes people with good looking.Some girls may be more attractive if they wear glasses.While some other girls may be more beautiful without glasses.So girls can try them on to decide whether they are suitable for glasses.