Lowering the gaze is of two types, one which a person can do and which he has no excuse for not doing, which means not repeatedly looking at women or deliberately looking at them. This is something that he can do, and it is obligatory upon him, I mean not repeatedly looking at women or deliberately looking at them, because it is within his capabilities, and it makes no difference whether he is in a country where there is a great deal of unveiling or not. 

The second type is something that a person cannot avoid, and it is an accidental glance, where he sees a woman but he does not look repeatedly at her or look deliberately; rather he carries on his way. This will not harm him and he is not sinning thereby, because it is beyond his control. This, and Allaah knows best, is the reason why Allaah says (interpretation of the meaning): “Tell the believing men to lower their gaze (from looking at forbidden things)” [al-Noor 24:30]. In the original Arabic the literal meaning is “lower some of the gaze” which means that lowering the gaze completely is not obligatory and it is something that is beyond a person’s control, or what is required in cases of necessity, such as a doctor looking at his patient and so on, or when a man looks at the woman to whom he wants to propose marriage. End quote.