They are worn for a couple of reasons.
1) If you have your eyes dilated (in the case of the Blues Brothers) by some chemical enhancements, the brightness of indoor lights (or bright sunlight) can make you almost totally blind from the excessive light overpowering your eye's retina.
2) If you ARE driving at night, your eyes are dilated from the general absence of light stimuli (it IS dark outside), and you don't want your sorry excuse of eye muscle(s) to take the many minutes to re-adjust to the light levels once exposed to bright light, they can be helpful.
Yes, some of those headlights are really loud. I remember back in the 70's when I had 100W headlamps for high beam, they really lit up the place. Flashing lights really did work!
Me? No I don't have any wearables at the moment. I found out that FitBits don't like Hawaiian salt water and will charge, but not really function.