I've just taken a look at mine, from the front in a darkened room, and crikey, yes, they are definitely an extremely bright, dazzling white, and yes possibly blinding. I was quite surprised as it's the first time I've ever taken an actual look at the light from a forward perspective. I just switch it on and go. Never have need to check as it's powered direct from the battery.
Nothing like those old large metal ones, powered by their own batteries, which you'd slot onto the front of the bike. They were very mild by comparison.
With that said, I certainly wouldn't be up for taking lectures from motorists who come at you full beam on an unlit road. I challenge any cyclist to stay fully orientated in direction before such a car passes.