God never blinds any sinner, but he often refuses to grant to some, in punishment for their ingratitude, the light that he would have given them had they remained faithful and grateful. Hence when it is said that God makes any one blind, it is meant that he withholds the light of his grace. This, therefore is the sense of the prayer, and lead us not into temptation; we ask God not to permit us to have the misfortune of being in those occasions of sin in which we might fall.--St. Alphonsus Liguori, The Holy Eucharist
