You see what you believe is there, and you believe it is there because you want it there. Perception has no other law than this. (A Course in Miracles)
Perception is seeing only that which you want to be true. It is to first adopt an opinion or mental position, and then to interpret the world through it.
Vision, on the other hand, is seeing only what is real. In vision, there are no mental positions or opinions. There is no labeling of good and bad, no judgment, no guilt, no naming, no debating.
Perception is identification with the mind. Vision is awakening to consciousness.
The thought system of perception is built upon separation, observing differences, determining who is right and wrong, who is guilty and innocent. The perceiver attempts to establish truth by convincing others through indoctrination, debate, or punishment and reward. The real result of perception is never of much concern. Suffering and destruction is tolerated as long as the perception is upheld.
Vision rests on logic beyond thought. It cannot be possessed, cannot be grasped, cannot be debated or proven. It is the knowing of the universe which manifests itself in the balance of all things. It is beyond time, beyond form, utterly beyond our control. It was true before the world exists and it needs nothing from us to remain true. In comparison, perceptions are of no concern one way or the other.
In human perception is struggle, chaos, endless war. In vision is the peace of God. We let go of perception and release our troubled mind to vision. We continue tomorrow and each day after that.