Mark 8:24 - Albert Barnes' Notes on the Bible

I see men, as trees, walking - I see men walking, but see them so indistinctly that, but for their “motion,” I could not distinguish them from trees. I cannot distinctly see their shapes and features. Probably our Lord did not “at once” restore him fully to sight, that he might strengthen his faith. Seeing that Jesus had partially restored him, it was evidence that he could “wholly,” and it led him to exercise faith anew in him, and to feel more strikingly his dependence on him.