when light comes from a source and hits something it reflects the light while some of it doesn't. when the reflected light or a light which hasn't been reflected comes to a certin place in the eye called the pupil. there we accualy see it upside-down untill our brain turns it back to right-side-up. And then our brain tells us what the objects are. That is how we see.
An expression used when one person has proven what he/she has said before to be true.
Guy 1: Hey
Guy 2: Hey
Guy 1: You should come by my house later, we could watch the game on my new 72" plasma.
Guy 2: You liar. There is no way you have a plasma that big.
Later, Guy 1 takes Guy 2 home, and Guy 1 Displays his 72"plasma
Guy 1: See?