Shielded Street Lights

The problem with streetlights are that they actually reduce your night vision. Lights bright enough to illuminate the earth some 20+ feet below them will be the brightest thing the eye pics up. Why have your pupils constricted to let in less light when you want to see better in the dark?

My idea is to angle streetlights away from oncoming traffic and to add a cowl so that the source of the light cannot be viewed while driving, but the lights still illuminate the roadway. For bi-directional traffic like highways, the cowl around the light would cut the light off to NOT illuminate the opposite side of the road. This way, cars travelling in opposite directions would not be illuminated by the opposing side side, thus preventing the glare from the oncoming lanes.

I think the cowls would also help reduce light pollution for astronomers, and star-watchers.

I originally envisioned this idea as a louvered cowl around the light, but did not see an advantage over turning the lights away from traffic, and using a more simple shade around the light.