Whenever I see any image of a black hole or in television or anywhere, I found there is a ring of light around the black hole. In discovery channel, I heard them saying that scientist found rings of light in space which had black region inside it. It was also one of the evidence with the help of which we can say that black holes are there in the universe. My question is that, when we know that black hole has sooo.... much of gravity that even light cannot escape from it, how can we see those rings of light ???? Means how that light is able to reach our eyes ????