Acts 22:11
And when I could not see for the glory of that light, being led by the hand of them that were with me, I came into Damascus. And when I could not see for the glory of that light, being led by the hand of them that were with me, I came into Damascus.
This is Paul's own account of his conversion in his encounter with Jesus on the way to Damascus. It was the glory of that heavenly light, the glory of Christ, that left him unable to see. When the light was withdrawn, darkness settled over his vision. The effects of that light remained in his eyes as a mark of Christ's glory.
Because he could not see, those who were with him took him by the hand and led him, and so he came into Damascus. His coming was the reverse of what he had intended, for the man who had expected to enter with power and honor to seize Christians entered helpless and dependent on others and deprived of sight. He believed this blindness was God's punishment upon him for persecuting the followers of Jesus.
He was burdened with remorse and was brought there in helplessness and fear, uncertain what the Lord would do with him and what judgment might follow. The blinding marked the experience that brought his proud heart to bow to Christ, the crucified Nazarene.