"Your lights are shining in my eyes"

[LittleWheelsandBig]

I know an experienced AUK who is susceptible to flashing lights. Emergency vehicles generally aren't in your field of view for minutes at a time.

[Cudzoziemiec]

I think there is also a thing going on with people buying really bright cycle lights and then actually sitting them to shine at driver eye height.

This is exactly what seems to be happening.  I think those who do so are naively thinking that they are assuring that they will be seen without realising the effect

I am entirely unconvinced that the word "thinking" has any place in your second sentence, or any place in their thoughts.

I disagree. We're continually told the value of conspicuity, hi-visibility, be seen be safe. Some people are reacting to that.

[Asterix, the former Gaul.]

I think there is also a thing going on with people buying really bright cycle lights and then actually sitting them to shine at driver eye height.

This is exactly what seems to be happening.  I think those who do so are naively thinking that they are assuring that they will be seen without realising the effect

I am entirely unconvinced that the word "thinking" has any place in your second sentence, or any place in their thoughts.

I disagree. We're continually told the value of conspicuity, hi-visibility, be seen be safe. Some people are reacting to that.

Reacting <> thinking though. 

Incidentally, I wouldn't be surprised if the strobe setting on some lights, particularly the very bright ones, could trigger epileptic fits in the susceptible.

Have there been any recorded incidents of this? I suppose those people who 'may' be affected should stay indoors,
in case an emergency vehicles goes past them.

Since my head injury I appreciate the problem exists.  Not only do I find flashing lights 'difficult', I find it quite hard to drive through some tunnels where the wall lighting is at eye level and also found it hard to cycle over streets with patterns in the road surface.  Large empty paved areas where the surface is unbroken and I have to try to ignore the lines if the sun shines across them.   

Altho' on UK roads I use my dynamo for a DRL, I think excessive lighting is counterproductive as well as unsociable, particularly to oncoming cyclists on cycle paths.  I've noticed that when boarding the channel tunnel it is good practice to switch off lights otherwise the boarding staff are continually faced with bright lights approaching them.

If anyone tried to make me stay indoors they would have to face the consequences!

[T42]

Incidentally, I wouldn't be surprised if the strobe setting on some lights, particularly the very bright ones, could trigger epileptic fits in the susceptible.

Have there been any recorded incidents of this? I suppose those people who 'may' be affected should stay indoors,
in case an emergency vehicles goes past them.

The strobe frequency on the Cree light I have is higher than that of the usual blue flasher - I'd put it at about 3 Hz.  If I close my eyes and shine it on my eyelids I can see some very pretty tiled patterns that appear to move.  According to the lit., if I can get it up to ~12 Hz the fireworks should be really great - interference with the scanning cycle of the visual cortex.

Folk who never knew they were epileptic can have their first fit triggered when driving along our straight poplar-lined roads at sunset. This happened to a few British soldiers when they came over the France in WW2. In one incident an officer nearly strangled his driver.

[T42]

Could be 4, I have no way of measuring it.

[frankly frankie]

Yes sorry - my comment removed after I checked my facts! - the legal frequency is in the range 1 to 4 Hz

[vorsprung]

A guy in a van once stopped me in a lane early evening to say that my lights were "too bright and shining in his eyes"

The light in question was a B&M Cyo 60 lux version so it was reasonably bright but not as bright as a dipped headlight.  Also B&M lights tend to try and put all the light on the road instead of up in the trees or the eyes of car drivers.  After a brief exchange of views we went on our way

Afterwards, I realized that on that lane there is a very slight slope so where I was coming from was downhill (slightly) from the van.  So this would raise the angle of the beam a small amount.  Add this to the van driver being a dick and that's the situation explained

[T42]

Could be 4, I have no way of measuring it.

Strike that: yes I have. My wee Nikon V1 will take a 5-second video at 40 frames/sec, then it stops.  I just took such a video: in the space of 5 seconds the lamp flashed 51 times, which puts it at 10.2 Hz. I suspect it's exactly 10 since the light was on at both start and finish.  So much for my "3 per second" estimate, but possibly interference with the eye's refresh rate intervenes there, I don't know enough about it to say.  10 Hz is very close to the alpha rhythm, which explains my pretty patterns.

[De Sisti]

I know an experienced AUK who is susceptible to flashing lights.

If the rider in question is experienced, he/she will know that flashing lights will (almost certainly) be used by other cylists,
so he/she should be experienced enough to avoid group rides then. Just sayin'.

[LittleWheelsandBig]

I believe the correct response to that post involves sex and travel.

You asked if anybody was actually adversely affected by flashing lights. The answer is yes. He deliberately doesn't draft folk with troublesome flashing lights but occasionally folk overtake and then slow down. Personally, I am happy to tell the overly-flashy to run on steady when in a group, which is the best option.

[De Sisti]

I believe the correct response to that post involves sex and travel.

I'm sure you're very familiar with that.


If someone is in a group where a flashing light is annoying them, and the person with the flashing light won't
change it to steady, then it's better to leave the group and carry on alone, or join another group where there
isn't a light that is annoying.

[LittleWheelsandBig]

Please continue to teach your grandmother to suck eggs.

The ideal solution is for riders in groups (do whatever you like when riding solo) to run steady lights.

[jsabine]

I believe the correct response to that post involves sex and travel.

I'm sure you're very familiar with that.


If someone is in a group where a flashing light is annoying them, and the person with the flashing light won't
change it to steady insists on continuing to be an anti-social wanker, then it's better to leave the group and carry on alone, or join another group where there isn't a lightdickhead that is annoying.

FTFY

[andyoxon]

On the way home earlier (not dark) saw someone with MTB on a dual-use path, flashing what seemed to be one of those ~5000 lumen facemelta front lights.     Not sure any oncoming peds/cyclists/motorists would being enjoying the experience...

[MikeFromLFE]

On the way home earlier (not dark) saw someone with MTB on a dual-use path, flashing what seemed to be one of those ~5000 lumen facemelta front lights.     Not sure any oncoming peds/cyclists/motorists would being enjoying the experience...

Indeed - there's a subsection of folk who can't get their heads round the difference between 'seeing' and 'being seen'

[recumbentpanda]

Riding through the longest of Bath's 'Two Tunnels' I encountered a large party of children on bicycles escorted by adults on some sort of holiday activity jaunt. This being the winter hols and not long after Xmas everybody had decided this was the ideal time to try out their new bicycle lights. As no one was much older than ten, these were pointing in every possible direction except backwards, and as a recumbent rider I was getting a large proportion of them in the face. In order to continue in a straight line, I shielded my eyes with a hand, palm outwards. As I passed the two adults at the back of the group I heard the following exchange: "Why has he got his hand over his face like that?" "Probably shy poor dear."

[Asterix, the former Gaul.]

Riding through the longest of Bath's 'Two Tunnels' I encountered a large party of children on bicycles escorted by adults on some sort of holiday activity jaunt. This being the winter hols and not long after Xmas everybody had decided this was the ideal time to try out their new bicycle lights. As no one was much older than ten, these were pointing in every possible direction except backwards, and as a recumbent rider I was getting a large proportion of them in the face. In order to continue in a straight line, I shielded my eyes with a hand, palm outwards. As I passed the two adults at the back of the group I heard the following exchange: "Why has he got his hand over his face like that?" "Probably shy poor dear."

 

[Mr Larrington]

I once found myself riding with my hands over the mirrors of my Trice while being followed in the closing overs of a 200 by Manotea otp and his Solidlight.  Then the road went upwards and he rode serenely off into the distance.

[mattc]

<snip of fun stuff>

If someone is in a group where a flashing light is annoying them, and the person with the flashing light won't
change it to steady, then it's better to leave the group and carry on alone, or join another group where there
isn't a light that is annoying.

If you know your rear light is causing annoyance, there is a simple compromise to keep everyone happy:
ride at the back.
As you chose your light for your own safety, you will get maximum benefit if there are no other riders behind you.

[T42]

Then there's the silly bugger who puts a couple of Decathlon's 8€ bugeyed elastic efforts on his saddlebag so that they point straight into your eyes,  bounce up & down and twist the eyes out of your head.

[Asterix, the former Gaul.]

<snip of fun stuff>

If someone is in a group where a flashing light is annoying them, and the person with the flashing light won't
change it to steady, then it's better to leave the group and carry on alone, or join another group where there
isn't a light that is annoying.

If you know your rear light is causing annoyance, there is a simple compromise to keep everyone happy:
ride at the back.
As you chose your light for your own safety, you will get maximum benefit if there are no other riders behind you.

Last group ride I did I got ridden into twice by following riders, once when a tractor made us all stop and then when someone had the brass neck to want to cross the road on a pedestrian crossing.   It's definitely safer at the back.

[CrazyEnglishTriathlete]

The issue seems to be that lights are marketed on the "more lumens the better"   

[T42]

Can never forget that a lumen is also the tunnel from one end of the gut to the other.  5000 lumens is a load of tripe.

[Kim]

The issue seems to be that lights are marketed on the "more lumens the better"

Like bike weight, this suffers from over-emphasis due to being easy to measure infer from the LED datasheet.  In practical terms it tells you nothing about how much light goes where.

The StVZO-compliant lights that specify their output in Lux are somewhat better, in that that does at least tell you how brightly the road will be lit.  It's still hard to quantify beam shape, and how the human eye reacts to it (for example, a 40Lux Cyo R illuminates the road better from a high angle than a 60 Lux Cyo, because the beam has less of a hot spot - and both lamps output exactly the same number of lumens).

But that's just about lights for seeing with.  About the only useful quantitative measure of be-seen lighting that you tend to see is beam angle, which says nothing about the point source effect.

[Cudzoziemiec]

Most nocturnal mammals and owls will stand a better chance of getting clear if you dip your lights. ... If you come across an animal in the road at night, slow down and dim your headlights as much as safety will allow until it has escaped.

The Roadside Wildlife Book, Richard Mabey
(Also has interesting things about why badgers are especially liable to road deaths; their instinct is to turn and face the danger head on to fight it off. "Almost all badgers found dead on the road have been struck in the head or neck.")