Slight tangent (apologies). Driving home down the A2 in Kent, I am often confronted by Cyclists riding on the pavement, towards me on my left hand side. The latest 'trend' is for them to have full scale working mock-ups of the Bell Rock - Light House, strapped to the front of their bikes, pulsing out about a gazillion watts with every flash of their light beam. If caught in this pulse of light, you may find yourself and your car, teleported to another galaxy, far away from planet earth. They are seriously distracting, very high powered lamps. My Son (who cycles every single day) tells me, these are sold as "safety lamps" and are indeed phenomenally powerful to the naked eye and also phenomenally expensive to buy. How does he know his? Ask his partner? When he arrived home with his newly purchased "safety lights" he decided to test it out in their kitchen....... Bad move... She says that 48 hours later she still had white spots (floaters) in her eyes and is not making this up.
Now on a cycle, wobbling around in the dark on your NS and heading towards you in pitch blackness, I would say that these present a hazard. They are best distracting to any motorists, at worst, useless to the cyclist as a visual aid. The darkness between each pulse must be blinding, as the human eye attempts to adjust to the rapid change between black & white?
I am not a big fan of motorcyclists who tint their headlights in a variety of colours. Again it is distracting and (I believe) illegal? You are simply not expecting to be confronted with 'Pat's Mobile Disco' heading towards you at speed on the AXXX. There is, that second, as your brain attempts to compute what it is that you are seeing? Is it a space ship? a set of flying traffic signals? motorbike with illegally tinted headlights?
I read yesterday (warning this maybe an urban myth, but I am assured it not?) of a chap in his 4x4 who was hit head on by another car, that was badly damaged (as was the 4x4). Police were called and driver of 4x4 stated "they were on my side of the road" occupants of the other car stated "we were completely blinded by his headlights". Police then find that the 4x4 has LED headlight bulbs and report this to both insurance companies. The 4X4 insurers "move" to void his policy for using "illegal off road use only" LED bulbs. The third parties insurers are looking to recover their costs through the courts and this includes "personal injury".
Being seen is only part of it. Being legal and insurable is the greater part. Stay Safe!!