+1 on what Rezdog said. I have rather large hands and can't see the blade on my face in a number of areas, but after a while developed quite a feel for where the blade is,especially relative to things like ears

On the more difficult areas like the chin and neck, I can see well. Near my sideburns where I have limited vision, I judge the angle by the single of the scales, and by twisting my head and neck around, I can get enough of a view to be safe.