How do Predators see things?

[IrocJeff]

I've been a fan since HBO first played Predator. I've seen them all, don't like some, but, from a technology/biology standpoint, how the hell do these things see anything? In the first movie, the predator takes of his helmet and we see that he sees in mostly red.

 

So, having watched all these films and whatnot I start asking myself this... How do they manage to differentiate between things? How can they build spaceships or, even more simpler, see where they are going? Is it only Earth's atmosphere that does this to their vision?

[Cerez]

I've wondered about this, too, when I saw the the first movie.  I think it's a combination of heat vision with a heightened aural perception, or something similar. It's definitely more than just heat vision. Whatever it is, it's perfect for hunting people, haha! 

 

Edit: They can also see using natural light, it seems, because they can visually distinguish details in their environment at all times.