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.
Two bous were palying hide and seek:
1:"I see you!"
2:"Than where am i?"
1:"behind the tree"
2:"How do you know?"
1:"The light reflected from you and the reflected light hit my pupil. when the light came to my eyes it was sent to my brain and understood."
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?