Curvy roads, and lack of light pollution in the sky, combined with probable sleep deprivation doesn't make for a good situation. Even if you stay on your side of the road, who says that other guy coming in your direction is doing as well?

Headlights in your face are not a very good way to keep track of traffic, neither is a complete absence of light where a car should be though. An optimal solution would probably be something that prevented getting blinded by oncoming headlights while still retaining enough visual cue to be able to perceive that a car is headed towards you and to track its position.