[Chad C. Mulligan]

This was true as far back as the '60s. We sporty-car types used European headlights because the worked better, but they were illegal because the DOT regulated design rather than performance.

LED headlights have an insurmountable problem in that the light-emitting surface ia much too large to be focused by any lens. This is why "low beams" still blind you.

[cymbeline]

“LED headlights have an insurmountable problem in that the light-emitting surface is much too large to be focused by any lens.”

The larger light-emitting service could be directed into a narrower beam with a longer-focus lens or reflector. With a reflector the light emitting surface would be aimed back toward the parabolic reflector.

Remember the large searchlights used especially during WW2 to illuminate enemy planes? Very narrow, intense beam produced by an electric arc.

Larger-diameter headlights used in older cars have become un-stylish, so we have the small headlights whose beams can’t be properly constrained.

Today’s LED headlights are dangerous and I’m surprised that the designs being used are allowed.

As an aside, the filament in incandescent headlight is oriented horizontally which allows good vertical constraint of the beam.

[Paal Gulli]

Every street bike (and/or car intended for “spirited” driving) I ever bought got Osram (German) headlight bulbs as soon as I could find a suitable model.