Confused about women covering their faces
Question

                First of all I must make clear that I have read your articles related to this topic. Although I have heard other evidences to suggest that the FACE veil is optional, due to the following:

(1)When the ayah was revealed commanding the believing women to cover (24:31) only the wives of the prophet covered themselves with a facial veil. The other Muslim women did not take steps to veil their faces.

(2)When some of the sahabah intended to propose to a women they would go and look at her without her knowledge. And of course if she had worn a facial veil they would not have been able to see her?

This topic is causing me much confusion please clarify the importance of the niqaab, I only want to do the correct thing for the sake of Allah.
Praise be to Allah.Firstly: 
We appreciate your keenness to find out the 
    truth and follow it, and we ask Allaah to show us the truth as truth and enable us to follow it, and to show us falsehood as false and enable us 
    to avoid it. The correct view regarding this matter is that it is obligatory for women to cover all of their bodies in front of men. See question 
    no. 21134.
 Secondly: 
Your saying that “the rest of the Muslim 
    women did not cover their faces” is not correct. Rather the command to observe full hijab applied to the wives of the Prophet  (peace and 
    blessings of Allaah be upon him) and his daughters and the believing women. The evidence for that is the verse in which Allaah says 
    (interpretation of the meaning): 
“O Prophet! Tell your wives and your 
    daughters and the women of the believers to draw their cloaks (veils) all over their bodies (i.e. screen themselves completely except the eyes or 
    one eye to see the way). That will be better, that they should be known (as free respectable women) so as not to be annoyed. And Allaah is Ever 
    Oft-Forgiving, Most Merciful”
[al-Ahzaab 33:59]
 And Allaah says (interpretation of the 
    meaning): 
“And tell the believing women to lower 
    their gaze (from looking at forbidden things), and protect their private parts (from illegal sexual acts) and not to show off their adornment 
    except only that which is apparent (like both eyes for necessity to see the way, or outer palms of hands or one eye or dress like veil, gloves, 
    headcover, apron), and to draw their veils all over Juyoobihinna (i.e. their bodies, faces, necks and bosoms)”
[al-Noor 24:31]
The command in these two verses is general 
    and applies to all believing women. 
Al- Bukhaari narrated that ‘Aa’ishah said: 
    “May Allaah have mercy on the first Muhaajir women. When Allaah revealed the words ‘and to draw their veils all over Juyoobihinna (i.e. their 
    bodies, faces, necks and bosoms)’ they tore their aprons and covered their faces with them.” See also question no.
    6991. 
Abu Dawood (4101) narrated that Umm Salamah 
    said: “When the words ‘to draw their cloaks (veils) all over their bodies’ [al-Ahzaab 33:59] were revealed, the women of the Ansaar went 
    out looking as if there were crows on their heads because of the covering.” Classed as saheeh by al-Albaani in Saheeh Abi Dawood. 
The Muhaajir and Ansaari women obeyed this 
    command and covered their faces. 
Thirdly: 
With regard to a man looking at the woman to 
    whom he wishes to propose marriage, this is part of the Sunnah. Abu Dawood (1783) narrated that Jaabir ibn ‘Abd-Allaah said: “The Messenger of 
    Allaah  (peace and blessings of Allaah be upon him) said: ‘When any one of you wants to propose marriage to a woman, if he can look at that 
    which will motivate him to go ahead and marry her, then let him do so.’ I proposed marriage to a girl and I used to hide myself until I saw that 
    which motivated me to go ahead and marry her, then I married her.” Classed as hasan by al-Albaani in Saheeh Abi Dawood, no. 1832. In the 
    report narrated by Ibn Maajah it says that he hid in her garden to see her. 
This hadeeth indicates that the women of the Sahaabah used to 
    cover their faces, because if it had been the custom for women to uncover their faces, there would have been no need to hide, because he would 
    have been able to see her in any place if she had been uncovering her face. 
But because it was the custom for women to 
    cover their faces, he needed to hide. It is well known that if there are no non-mahram men around, a woman does not cover her face, such as when 
    she is in her house or in her garden, as in this hadeeth. 
And Allaah knows best.