In reply to Tony the Blade:
the 'short' peak is of a perfect size to prevent the spray from the rear wheel infront of you, that you are busting your guts to stay in the slip stream of, from flicking into your eyes. The spray 'arcs' up ont the peak and is of adequate length to enable you to see up the road (past the bike in front).
And on dry days the peak drips the sweat from running down your face.
absolute necessity if like me you have inadequate eye brows to act as guttering.