Dr. Zakir Naik claims that it is not fard to cover the face in Hijab. But Dr. Israr does not agree with this approach. He says that covering of face is the most important part of Hijab.
In this lecture Dr. Israr has discussed the Sharia rulings of Pardah in general. He has also discussed the issue of face covering in detail. So please watch the whole lecture. Inshallah it will be very helpful to you in understanding the essence of Pardah and fardiat-e-Niqab.