A couple of nights ago I was preparing to swing out past a parked car (in the cycle lane, sigh) so I signalled and glanced behind.
I was met with a light so bright I was momentarily dazzled before black spots began appearing and it took a few minutes to recover. Luckily there wasn't much traffic so my temporarily impaired vision didn't lead to an accident.
I can hear you thinking that surely this must have been a car with its lights on full beam. Nope. It was a cyclist.
In the last couple of months I've seen a real increase in the number of cyclists carrying incredibly bright, and expensive, lights on their handlebars. On one level I'm pleased that some cyclists are taking their lighting seriously, those without the legally required minimum shouldn't be on the road, but on another I find the escalation of it a bit tiresome.
On winding and remote country lanes and in some suburbs I can see why you would need a light capable of exposing every pothole and obstacle and, in narrower stretches, you may well need a light that signals your presence for tens of metres so that cars don't come haring round corners and squish you. But surely, even in these circumstances they should be pointed at the ground, not full ahead where other cyclists and drivers will be blinded by them?
In London, where the roads are lit by street lighting, bike lights are primarily to let drivers know you're there aren't they? Quite frankly enough people cycle comfortably (if not safely) on-road without any lighting whatsoever to prove that they're primary purpose is not to light the way ahead.
Maybe I'm wrong but you won't see me investing in anything above 100 lumens (or whatever they're called) any time soon.