Dear Tom and Ray:

Is it my imagination, or are headlights getting brighter? Have you traveled at night recently? I flash the brights so the oncoming driver will dim his car's lights, and he flashes his brights back to show me they're already dimmed! It takes awhile to get your bearings when all you can see is white dots. Older cars' headlights seem to have a more yellow color, whereas the new cars' lights are bright white. What's going on? -- Don

TOM: What's going on is that headlight technology is changing. Again.

RAY: Cars used to use incandescent lights. Then brighter halogen bulbs came into use in the '80s. And now, car makers are beginning the transition to xenon headlights -- also known as "high-intensity discharge" lights. They're mostly found on high-end, expensive cars these days, and they have a bluish tinge to them.

TOM: And from the driver's point of view, they're magnificent. Their light pattern is supposedly the same as standard headlights, but the xenon bulbs deliver bright light all the way to the edges of the pattern, which means you see more of the road.

RAY: And the xenon light is whiter and brighter -- and more like daylight, too. So when you drive with xenon headlights, especially on a really dark road, you really do see a lot better.

TOM: But there are several things that are creating problems for oncoming drivers. One is that they're not used to these new lights, so people tend to stare at them as they drive by and say, "What the ... ?" And, as you say, that leads to the white-dot phenomenon.

RAY: The same thing happened when halogen bulbs first came out, according to the folks at the National Highway Traffic Safety Administration (NHTSA), as the eye is unconsciously drawn to brighter objects.

TOM: Some of the new lights are also incorrectly aimed. It's bad enough when a conventional headlight is pointed toward your eyes, but when one of these babies is off kilter, it can really be dangerous to oncoming drivers.

RAY: And according to NHTSA, a major problem is that there are lots of blue-tinted knockoffs available in auto-parts stores that don't meet federal standards. Those are just as bright, but not as well-focused as the legal xenon lights.

TOM: And until the xenon bulbs come down in price (they're currently a $500 to $1,200 option on some cars), the cheap knockoffs will probably continue to be available. NHTSA has received a pile of complaints, and police organizations are trying to come up with simple guidelines to help them pick out and ticket offenders.

RAY: But it doesn't look like anything is going to stop the xenon onslaught now. Like most automotive technology, it'll work its way down from the Mercedeses and BMWs to the Fords and Chevys in a couple of years. And then maybe we'll all have to wear sunglasses at night. Ah, progress.