Finally, there are many hadiths from Prophet Muhammad (s) and the Ahlul Bayt (a) about hijab. Some people think that hijab is not something that was taught by the Prophet himself, but was made up by people later on. However it is certainly rooted in the Holy Qur’an. As explained previously, it existed before the advent of Islam.
There are ten verses in the Qur’an specifically about it and then the Holy Prophet (s) mentioned it with so much care and giving so many details. Those who are interested can find tens of hadiths in major collections of hadith. In what follows, I will refer to some hadiths to illustrate how delicately hijab is treated in Islam.
Prophet Muhammad (s) advised ladies to be careful about their hijab when in their homes. For example, sometimes even when a lady is inside her house, her neighbours may still be able to see her when she stands next to the window, goes out into the courtyard, or goes onto the roof (as people do in eastern countries). 
Furthermore, Umm Salamah, the wife of the Holy Prophet, (s) said:
عَنْ أُمِّ سَلَمَةَ قَالَتْ كُنْتُ عِنْدَ النَّبِيِّ ص وَ عِنْدَهُ مَيْمُونَةُ فَأَقْبَلَ ابْنُ مَكْتُومٍ وَ ذَلِكَ بَعْدَ أَنْ أَمَرَ بِالْحِجَابِ فَقَالَ احْتَجِبَا فَقُلْنَا
يَا رَسُولَ اللَّهِ أَ لَيْسَ أَعْمَى لَا يُبْصِرُنَا قَالَ أَفَعَمْيَاوَانِ أَنْتُمَا أَلَسْتُمَا تُبْصِرَانِهِ
One day Maymunah and I were with Prophet Muhammad (s) and Ibn Umm Maktum who was blind came to see the Prophet (s). The Prophet (s) asked us to have our hijab. We said: “O Apostle of God! Ibn Maktum is blind and is not able to see us”. The Prophet (s) said: “Aren’t you able to see him?” 
Thus, it is not proper for a lady to appear without hijab next to an un-related man, even if he is blind. Whilst it is true that that the blind man cannot see the lady, it cannot be forgotten that she can see him, and this may have an effect on her. In some cases, it is also possible that the man is pretending to be blind.
In a hadith about Lady Fatimah (a), we find that instead of the Prophet (s) or Imam Ali (a) telling her what to do when there is a blind visitor, she autonomously put on her hijab:
عَنْ مُوسَى بْنِ جَعْفَرٍ عَنْ آبَائِهِ ع قَالَ قَالَ عَلِيٌّ ع اسْتَأْذَنَ أَعْمَى عَلَى فَاطِمَةَ ع فَحَجَبَتْهُ فَقَالَ لَهَا رَسُولُ اللَّهِ ص لِمَ حَجَبْتِهِ وَ هُوَ لَا يَرَاكِ فَقَالَتْ ع إِنْ لَمْ يَكُنْ يَرَانِي فَأَنَا أَرَاهُ وَ هُوَ يَشَمُّ الرِّيحَ فَقَالَ رَسُولُ اللَّهِ ص أَشْهَدُ أَنَّكِ بَضْعَةٌ مِنِّي
Imam Ali (a) reports that a blind man asked permission to visit Lady Fatimah (a). Upon hearing this, Lady Fatimah covered herself. The Holy Prophet (s), in order to illustrate her (a) level of understanding and knowing too well what her (a) response would be, asked: ‘O Fatimah! Why are you observing hijab when this man is unable to see you?’ She (a) replied: ‘He cannot see me but I can see him and he can smell my fragrance.’ In response to her wisdom, the Prophet (s) said: ‘I bear witness that you are part of me.’ 
So this is the way in which the Holy Prophet (s) and the Ahlul Bayt (a) very carefully observed hijab.
According to another well-known hadith, one day the Prophet (s) asked his companions: ‘What is the best for women?’ No one was able to give the right answer. Imam Ali (a) then asked Lady Fatimah (a), and she replied: “The best for women is not to see men who are not her close relatives (non mahrams) and not to be seen by them.” When the Prophet heard this, he was very pleased, and said: “Truly, Fatimah is a part of me.” 
After their marriage, Imam Ali (a) and Lady Fatimah (a) asked the Prophet (s) to advise them as to what their duties are. The Prophet (s) instructed that Imam Ali (a) should undertake the tasks outside the house and Lady Fatima (a) should undertake the tasks inside the house. Lady Fatimah (a) said afterwards: “Other than God no one knows how happy I became when the Apostle of God saved me from interacting with men.” 
With hijab necessary contacts are fine. From a spiritual point of view, unnecessary contacts should be kept very much to a minimum or if possible completely stopped, even though this may not be obligatory from a jurisprudential point of view.
A woman can be very active in society but this should be only for doing something useful and productive with which she can feel very happy and satisfied such as teaching, nursing and seeing patients.
A woman should not be just wandering around on the streets, going to different places and talking to many people, without any good reason to do so. This is not good for a lady and would also gradually exhaust her because a woman is created like a flower. Imam Ali (a) advised Mohammad ibn al-Hanafiyyah not to assign women difficult tasks and to treat them cordially under all circumstances. 
So a woman should not exhaust herself, and the family should not let a lady exhaust herself, by doing unnecessary things.
May Allah increase our understanding of His creation and His plan for us! May Allah make our families and societies stronger day by day! May Allah bring that peace and tranquillity that He has planned for us into our life!