There are three kinds of look to female strangers as:

1- A sinful look, i.e. you look once and keep it on.

2- A look which is not only a sin but it is the great Jihad, i.e. you have a glance at once and your carnal soul obsesses you to continue, but you stop looking for the sake of God.

This completely brings about divine reward.

3- A look which is neither good nor bad, i.e. you have a glance at female stranger unintentionally and your mind is not occupied with him.