thats permanent retinal damage at this stage: they kinda deserve it thou. use of led light need to be prohibited by the geneva convention or something, in the same category as cluster bombs ot sarin gas
although they dont break like incadescent bulbs and efficient in this regard, they shouldnt be that bright. also when its too bright they heat fast and that take away from their working life
Maybe look out for "mirror foil window"
At least my school had it and so many people where styling their hair in the "window mirror" without seeing that inside a bunch of students where laughing at them so it should be offective enough to shine back to the other cars