Lower lights (ie: fog lights) that illuminate the ground closer to the car rather than further away only hurts night time distance vision unless you're an unnatural alien, sorry to put it bluntly. If the ground is brighter near the car your eyes will not dilate as much and so you will not be able to see darker things further down the road. It's science and no humans eyes dilate in reverse. Don't let the fact that you see more closer up with fog lights on fool you into thinking you can see better further down the road. If you do visual testing yourself (ie, pull off a road somewhere where you can test and evaluate your vision at the far reach of your low beams). You will notice that extra light near your car from fog lights will make darker objects further down the road harder to see because your eyes are less dilated. An exception would be if your fog lights added no light within the first 50-100 feet on the road, but if that's the case you would have a fog lamp alignment problem.
There was also a study I read a while back that said using fog lights help only up to about 20-25mph for near vision at slow speeds, but after that it (as I found out in my own testing which caused me to research this) it only hurts vision. Most regular low beam headlights are also only helpful up to about 50-55mph. Over 55 you should be using high beams and if you live in a City you'll notice that freeways and roads with speeds over 45-50mph almost always have overhead lights when high beams aren't practical due to oncoming traffic to help with seeing objects further down the road.
I for a few years were just like you and thought fog lamps helped my night vision until I turned them off (can't remember why) and then noticed that once my eyes adjusted I could see much further at higher speeds. I like the look of fog lights on most all cars but I had to give in because I knew it was safer to drive without them.
I used many types of more pure white lights to help improve my night vison. Silverstars Ultra were my favorite but the John Deer tractor lights that gave you extra lumens (not as white though) due to a special coating that would produce a brighter burn but with the standard 55w power source. I did my research on night vision to help the best I could with the resources around starting about 10 years ago.
I personally opted for xenon for night vision on my X1 and it really does wonders for my night vision. I drove 1800 miles in 6 days and over 8 hours after dark up to 2am up to 85mph and never once had a hard time seeing at night or felt like my eyes were strained. I honestly was surprised how well my vision was at night, for my eyes personally there is a huge difference. I also tried using my X1 fog lights and had the same experience as with my Toyota, the fog lights made the ground closer to the car brighter and thus reduced my distance vision when dark out.
I got back from my ED into my halogen lamp car and frankly I don't like driving at night now in it. I can easily tell I don't see as far down the road or as many darker objects.
Also, with Xenon a benefit is it's closer to natural light so you eyes can use both rods and cones in your eyes whereas with more yellow light your eyes can not use the cones as well to see color and detect objects as well. You can read the studies that cover these areas but if you take 20 minutes and do a honest, unbiast test for yourself, I think you'll be surprised the results about fog lights not being better for night vision. I had myself fooled for years so I'm just trying to pass this information along.
For myself with light sensitive eyes, I don't think I will ever get a car without xenon again if I plan to drive it at night.
And I sometimes wish I was a LEO so I could pull over d@mn jacked up truck and suv with aftermarket and misaligned HID low beams and even sometimes HID fog lamps that fully blind me when coming head on. I'm pretty patient but being blinded at night by an arrogant, selfish idiot driver takes all my patience not to head on him and sue because I know myself and everyone else he passes can't see for about 5-10 seconds. I don't even bright him because I know that would only make the situation worse. Just like the older european car drivers who drive with their rear fog light turned on. Morons. If I see them I just know to stay away because they're not the smartest person if they do that. People who drive with fog lights I just know are people who are more into fad and looks than actual 'drivers' and car enthusiasts who know a little about cars.
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