I apologize for the click-bait title. Please indulge me for a moment before I get on topic.
I'm in the midst of retrofitting LED projectors into my 2006 Insight
. While doing so, I have been inspired to write about my observations with respect to lighting that uses the standard reflector housing.
Forget HID and LED retrofit bulbs, the most important thing you can do to improve your headlights is to ensure your lenses are clear.
Not only will doing so improve visibility for you, it will also reduce glare for oncoming drivers.
Note: this also assumes your headlights are aimed correctly.
After sitting for over two years since the last polish, here is a halogen low beam from my 2006 Insight.
At first glance, it may not look too bad, but after 30 minutes of polishing, consider this:
With less light being scattered by the clearer lens, light output is dramatically improved. And, with the light from the halogen bulb now properly focused under the cutoff, the road will be better illuminated allowing you to see further.
As an added bonus, notice how much less light there is above
the cutoff? This is good for everyone you share the road with as there will be less glare from your headlights. A win-win.
Speaking of glare, this is time to talk about alternative bulb technologies, namely HID and LED retrofit bulbs.
HID: I've seen a few Insights with HID retrofit bulbs installed, and they have been pretty bad with poorly defined to non-existent low beam cutoff.
LED: I have personally tried a set of $200 Phillips branded, H4/9003 LED retrofit bulbs and while not as bad as the HID retrofits I've seen, errant light scatter, i.e. glare for oncoming drivers, was still worsened.
Here is a before and after pictures of the lens.
Clearer, but still room for improvement.
Hopefully it's clear how much better the light output is, even from a not-perfect polishing.