Is there a law that dictates how bright headlights can be in the USA?

Question

im noticing more and more cars with these BRIGHT headlights, there as bright as normal headlights would be if you had them on high beam,there also a different color, like bluish (i think there halogen lights or something)anyway there so bright plus that horrid eye piercing blue that im blinded by them if there in the left turn lane or if im on a two lane highway, i always thought there was a law against that.

Answer 1

those bright bluish-white lights are called high-intensity discharge (HID) lamps and they are illegal in the US and the EU except for the 4300K HID temperature rating. they also are bright but do not cause blinding to oncoming traffic.

Answer 2

The laws vary by state. Most have a maximum and minimum headlite height, a specific number of lights, a limit on candle power, and an aim requirement. These laws are to prevent just what you describe, but are only really enforced in areas that require a state inspection, just by the licensed inspector.  

Sometimes an officer will give a warning to an obvious offense, but they have no on hand tools to actually measure anything except window tint, thus a citation would not hold up in court. And, it would be hard to even hold an inspector liable, because lots of folks change things enough to pass, then put them right back where they were.