I find the opposite. My helmet light is a narrow, spot beam. When I'm in normal riding position it points at the ground about 40 ft away. To light up a driver or a mirror, I have to lift my head. So the light is not in people's eyes, unless I want it to be.

The situation where my helmet light is too bright is on a dark path, especially where cyclists or pedestrians are coming toward me. I turn it off there. It is really meant for riding in traffic.