My apologies, I realize my last post wasn't very helpful - it was late last night, and I was tired. Shouldn't post when I'm tired.
I've found that water on the visor isn't that bad. It's not nearly as bad as water on the car's windshield, because of a couple of factors. First, the visor is much closer to your eyes, so the effect of water on your eyesight is not that bad. You actually see through the rain drops on your visor. I've found that it's not that bad. You can still see quite clearly.
Then, when needed (which isn't that often), a simple swipe of the glove is plenty to keep your vision crystal clear. It helps to have gloves with a chamois-like material on the back of the index and middle fingers, for wiping. I prefer that to the squeegee type of device, because for the squeegee to be effective you have to align it to the visor on-the-go, and it usually takes a few swipes because the squeegee isn't that long (wide). I've used both devices and prefer the integrated chamois-like material. Maybe I'm not coordinated enough for the squeegee.
The second factor is because the visor is much more curved than a car's windshield, if you turn your head a few degrees left and right, the wind does a good job of clearing the water. Like others upthread have said.
Hope this is more helpful.