When Jesus walked the earth and began his ministry here, one of the things that He did that showed people His power was to heal the blind.

Those who were healed believed in His power to heal even though many did not know that He was the Son of God. They accepted that He must get His power from Heaven because who else could bring sight to the blind?

Jesus was speaking to the religious leaders when He said this. They were not blind physically but spiritually. They arrogantly thought that they had all of the answers and Jesus in this one statement shows them how ignorant they actually are. Of course, these same leaders were part of the crowd who plotted against Jesus since they didn’t like being “called out” like that even though it was truth.
There are many today who are blind because of illnesses or defects or diseases. My sister has macular degeneration and has lost much of her eyesight. I pray for her to keep her sight as long as possible, but more than that, I pray for her spiritual eyes to be opened. She asks me to pray for her when things are going wrong for her, but she also claims not to believe in God, heaven or hell. Her spiritual eyes have been blinded, much like the Pharisees who ridiculed Jesus.
How many people in your life are spiritually blind? Before you can reach them with the gospel message, there needs to be a falling away of the scales from their spiritual eyes. God needs to prepare their hearts to hear and receive, and I think that comes with prayer. Does that mean that this is an impossible task? God says nothing is impossible with Him. So, I continue to pray for those who are blinded that they may see the truth. It is only when we realize that we are blind that we want help and that is how they are, too. They are so blinded that they don’t realize it and thus they remain in their sin. As believers, it is up to us not just to share the good news but also to pray that the hearts of the people with whom we share will be prepared to hear, understand and accept the truth. The blind can see, but we are the only ones who can help them to do so.