It could mean I’ve seen something for the second time; perhaps it means that I have another keener, better eye; I suppose you could infer that the sight was just for a second. . .in any event, “second sight” can be interpreted in any number of ways. I will leave it to you to decide what it means for you. Because what all language really comes down to is that there are no absolutes in interpretation or reading. We are all on our own. It amazes me sometimes that we are able to understand one another to the degree that we do. I don’t know why it surprises me when we don’t understand one another! Truth be told, I have a feeling that we misunderstand far more than we realize.
So, I leave it to you to figure out why I’ve decided to use the following photos as illustrative of “second sight.” Whether you understand or not is inconsequential in this case. Just enjoy.