As you all know by now, something terrible was released on the world last September. The cinematographer of John Carpenter’s The Thing (1982), Dean Cundey, revealed that there is a way to determine who is a Thing at the end of the movie:
So we were looking for some kind of a subtle way, to say which one of these (men) might be human. You'll notice there's always an eye light, we call it, a little gleam in the eye of the actor. It gives life.
Eyes that reflect light are human; eyes that do not …
With that in mind, here’s the last scene: