That has always been a pet peeve of mine. Vans, SUVs, and PU lights designed to be just a little higher than sedans, so when behind me, at night, they shine directly into my rearview mirror. I've found a solution. Works nearly every time. I adjust my outside mirrors a little out and up so that they shine back at the driver behind me. I also don't get why people seem to be,more and more, turning there lights on during the day. I guess they must think it's safer. It's NOT. The exact opposite of safe. You're shining a fosused light directly in somebodies eyes, be it day or night. Try my trick. It works. They either back-off or pass.
daytime conspicuity is why they are on during the day. there is research on this - most cars now have day lights for a reason. i would NOT ride my mc w/o lights on ANY time. lights on @ day= good idea. " But officer, I never saw him!" if they don't see me they are certified blind and my lights don't shine up in their face...
especially at night, don't look at the lights - bright or dim! look instead over to your fog line. you will still see oncoming just fine without being temporarily blinded.