my primary light is fork mounted, and difficult to safely reach on curvy, bumpy, MUPs. i realize it can be very bright, but hope that oncoming people have the brains enough to not act like deer and stare into the white. my light has no dual-brightness mode (unless you count turning it off and draining the capacitor---very difficult to do safely while moving). the beam is shaped/focused, but on MUPs is still bright enough to stun kids smoking pot in the darkness. too bad for them.

when it happens that i encounter another bright light (car or bicycle), i use the visor on my helmet to block the brunt of it and keep focused on the edge of the road or path. this always works for me. always. if it happens that you can't see the path, then you need to slow or stop to evaluate that condition, and not fault some other user's light. that's part of riding on varying road conditions.

on the other hand, if it's some moron with a headlamp aimed directly at my eyes, i have the option of returning the favor with my helmet-mounted light. it's my version of flashing my brights at another car. all in all, i approve of bright lights on the bicycles, and live with the consequences of others who feel the same. worse things can happen (like road salmoning with dark clothes and no lights at night).