If true vision comes from God, then not to have true vision is also from God in at least some sense. Undoubtedly our failure to see what God sees is because our perception has been obscured and perverted by our depraved nature. But if God bestows vision on some people despite their depravity, then God's disinclination to give it to others constitutes his decision to withhold it from them.
This idea might make people uncomfortable, but there is some subtle corroboration of it in the Gospel of Luke.
In Luke 9:43-45 Jesus tells his disciples that he is going to be betrayed. "But they did not understand this statement; its meaning had been concealed from them, so that they could not grasp it."
In Luke 19:41-44 Jesus weeps over Jerusalem: "If you had only known on this day, even you, the things that make for peace! But now they are hidden from your eyes."
In Luke 24:13-35 two of Jesus' disciples (not among the Twelve) are walking to Emmaus two days after Jesus had died. The risen Jesus encounters them and explains to them why it was "necessary for the Christ to suffer these things and enter into his glory" (v. 26), but "their eyes were kept from recognizing him" (v. 16).
Who concealed Jesus' prediction of his betrayal from his disciples? Who hid the things that make for peace from Jerusalem? Who kept the disciples' eyes from recognizing the risen Lord? God did.
The underlined phrases above are best understood as what are called "divine passives." Divine passives are verbs in the passive voice that respectfully avoid identifying God directly—e.g., "they are hidden" rather than "God hid them." Divine passives are not unusual in the New Testament, and these three examples seem to fit the mold, because God could tear the veil off whenever he wanted to (as he did with Saul/Paul, for example). And in fact, he did.
Notice that though God concealed the meaning of Jesus' prediction of his betrayal in Luke 9, in chapter 24 Jesus "opened their minds so they could understand the scriptures" that were fulfilled by that betrayal.
In Matthew's rendition of Luke 19:41-44 Jesus says, "You will not see me from now until you say, 'Blessed is the one who comes in the name of the Lord!' " The one who hid the things that made for peace will eventually make Jerusalem yearn for the one coming from him, and he will open their eyes to see him.
And with the two disciples headed toward Emmaus, God kept them from recognizing Jesus only until the moment that Jesus broke the bread, when "their eyes were opened" (v. 31, another divine passive).
So why does God do this? Why does he choose to keep people from gaining vision? Timing. God is a God who reveals, but he gives the vision at the right time for each person according to his perfect plan. So what does this teach us about vision? Two things.
First, we simply cannot take credit for vision, ever. The God who gives it is just as powerful to keep us in the dark. He deserves all the credit, we none.
Second, if we have the vision but others don't yet, we must remember that they never will until God is ready to open their eyes. Jesus did not successfully communicate true vision about his impending suffering to his disciples, and it wasn't because Jesus was a poor communicator. It was because God had concealed the plain truth that Jesus was speaking.
Though we can't blame people for our poor communication, our excellent communication of the vision must be accompanied by patience, because we know that only God will open their minds to grasp it. And the patience must be accompanied by confident trust that God's timing is always best, and he won't let them see until it is just the right time.