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Author Topic: Why can't I see at night?  (Read 14374 times)

Offline geo driver

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Why can't I see at night?
« on: 10/12/2009 01:02:01 »
well actually i can but..

i am a biker and i ride all year round (apart from in snow and ice) but, in the rain at night i find that a massive glare from on coming headlights means i cant even see 20m in front off me. i cant see where the road is going. as you can imagine this is kinda disturbing.

my theory is: my visor is too old but clean, and all the tiny little scratches (that i cant see) causes water to stay on the visor therefore when i have white light coming towards me, the light, scatters across the entire visor and make it impossible for me to see any further.

i have noticed that colored lights although distracting do not have such a profound effect.

i will by a new visor but what do you guys and gals think
« Last Edit: 11/12/2009 09:09:54 by chris »


 

Offline PhysBang

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Re: Why can't I see at night?
« Reply #1 on: 10/12/2009 03:18:41 »
Have you been getting enough vitamin A? Vitamin A deficiency can lead to loss of night vision.
 

Offline Mr. Scientist

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Re: Why can't I see at night?
« Reply #2 on: 10/12/2009 04:14:40 »
How old are you, if you don't mind my question :)
 

Offline Don_1

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Re: Why can't I see at night?
« Reply #3 on: 10/12/2009 08:59:16 »
I think there is also a problem with the modern lights used on cars today. They are so much more intense than older type lights, that alignment becomes more critical.
 

Offline geo driver

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Re: Why can't I see at night?
« Reply #4 on: 10/12/2009 12:37:11 »
im 31 and my eyesight is perfect. last night i had the same problem. it was not raining but there was a fine spray comming from other road users.

i had a thought...  could it be, that the reason coloured lights arnt so bad (the tail lights on a car) is besause that its only 1 colour of the light spectrum leaving the rest of the light sperctrum for me to see
 

Offline LeeE

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Re: Why can't I see at night?
« Reply #5 on: 11/12/2009 01:39:27 »
The effect of water droplets on your visor will be to increase the amount of light entering your eyes; instead of just the light entering through the area of your pupils you'll get light refracted into your eyes from a large proportion of the much greater area of your visor.

Then on top of that, when your eyes detect a bright light your irises will contract to reduce the amount of light entering, reducing their sensitivity; anything that is only lowly illuminated will become too dark to see until your irises open back out again.
 

Offline geo driver

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Re: Why can't I see at night?
« Reply #6 on: 11/12/2009 08:50:56 »
love it guys cheers
 

Offline Farsight

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Why can't I see at night?
« Reply #7 on: 11/12/2009 14:49:55 »
My wife has this problem. But she doesn't ride a motorbike, she's got cataracts. She isn't blind and it isn't getting worse, it's just how she's always been. The only way you can tell is that her vision when facing bright light is noticeably poorer than mine. Opticians have said "no, don't be silly", and then when they actually looked they've said "Oh my!". Geo, if that new visor doesn't seem to fix it, have your eyes checked.
 

Offline geo driver

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Why can't I see at night?
« Reply #8 on: 11/12/2009 18:17:48 »
cherrs farsight will do but that doesnot explaine why coloured lights dont have as much of an effect
 

Offline itisus

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Why can't I see at night?
« Reply #9 on: 11/12/2009 18:55:47 »
cherrs farsight will do but that doesnot explaine why coloured lights dont have as much of an effect
The "colored" light probably isn't as bright overall, and refraction angles should be more limited so it blocks less of the scene.
 

Offline techmind

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Why can't I see at night?
« Reply #10 on: 12/12/2009 13:36:18 »
The problem with night-driving is the extreme contrast between the very dark road ahead (even with headlamps) and the extreme brightness of oncoming drivers' lights.

The bright oncoming lights can cause your pupils to close temporarily, which restricts the amount of light coming into your eye and will make it much harder for you to see any detail in the 'dark' parts of the scene.

The second effect is that any scratches or slight mist/haze on the windscreen or visor scatter the incident light producing a 'glare' over your entire field of vision -which effectively raises your 'black level'- again masking all detail darker than that threshold. (The is the same effect experienced by people with cataracts.)

A clean, scratch-free, mist-free, visor will help.

I don't know whether you can get anti-reflection-coated visors but there is reason to believe they may also help under the circumstances described. The oncoming light will light your face through the visor, and the reflection of this in the visor will again raise the dark-threshold. Wearing a black balaclava under the helmet might achieve a similar improvement!

(Anti-reflection coated spectacles improve the blackness of black text on a white background for the same reason - in the absence of the AR coating a reflection of the eyeball is superimposed on your view.)


Either some people have remarkably good night-driving vision, or they drive as if they do, when they don't. As a driver I'm fairly conscious of haze on my windscreen (and wash/wipe the inside and out every few weeks) - I find it disturbing when I notice the windscreen of the car in front 'light up' as an oncoming car approaches... and realise just how little that driver must be able to see.


Take care!
« Last Edit: 12/12/2009 13:42:03 by techmind »
 

Offline yor_on

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Why can't I see at night?
« Reply #11 on: 12/12/2009 21:06:55 »
I know what you mean, but the kick of a good bike more than weights it up :)
« Last Edit: 12/12/2009 22:24:06 by yor_on »
 

Offline geo driver

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Why can't I see at night?
« Reply #12 on: 12/12/2009 21:42:44 »
tech you sound spot on i do wear a black balaclava but when there is some spray or wet weather riding can be difficult.  if i were a girl my name would be prudence. winter is no fun either as i have the pleasure of my visor misting up on the inside. but there is things i can do to combat that

1 get a new lid with a visor insert
2 take extra care wile riding
3 b4 it gets too cold buy a car

but riding is awesome, and a car would increase journey time buy 2-3 hours and paris is a nightmare for parking and driving i find it safe by bake surprisingly enough
 

Offline yor_on

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Why can't I see at night?
« Reply #13 on: 12/12/2009 22:20:46 »
Isn't there visors treated not to develop that mist? Thought I read about it somewhere? Not that I ride in the winters though. Perhaps France or at least Paris have relatively warm winters? I mean, driving a bike on ice? Then I would expect you to need special tires and heated handles etc. I use to drive as fast as I can but the wind in early spring normally leave my hands as ice blocks needed to be pried of the handlebars. And 140 HP on a backwheel leaves a lot of of 'prudence' to be wished for :)

----

Okay rereading you I see that you don't. For a moment I though you were like a guy I heard of here. He drives his bike the whole year around. But he 'rebuilds' it for the winters, and as I understood it it had to be a relatively 'calm' sort of bike. Mine is a Suzuki RF 900. And I would probably be dead, or at least hurting quite a bit, some minutes after taking off. if I rode it in the winter.
« Last Edit: 12/12/2009 22:32:03 by yor_on »
 

Offline geo driver

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Why can't I see at night?
« Reply #14 on: 12/12/2009 22:26:20 »
mines only 100 hp but still goes some.  the best thing i could find is an insert that stops the visor misting by traping air between the visor and the inserts.  you can get a treatment but thats only if you dont intend on cleaning the visor as you end up wash the treatment away.  but theses things can be expensive.  i also do on average 21K a year so you cna imagen the amount for washes the lid goes through
 

Offline yor_on

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Why can't I see at night?
« Reply #15 on: 12/12/2009 22:33:32 »
A hundred will get you dead too :)

So, any accidents?
And what was your first thought when having it?

(Yes I have a theory there:)
 

Offline yor_on

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Why can't I see at night?
« Reply #16 on: 12/12/2009 22:37:24 »
Yeah, my solution is to open the visor those times to get the air to blow it clean, as well as using my hands as some sort of wiper blades. But hey, there is always somewhere that waits for you, a cafe' or home or.. And then my friend :)
 

Offline geo driver

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Why can't I see at night?
« Reply #17 on: 12/12/2009 22:50:41 »
honestly i i do all thoezs thing and yep ive come off a few times.  the last time i rode into a wiled boar and what i was thinking at the time was..... my wife is gonna kill me.  straight up but i saw somthing mive in the corner of my eye and i thought hummmmmmm that snot right i best slow down a bit. the thing move right into my path.
 

Offline yor_on

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Why can't I see at night?
« Reply #18 on: 12/12/2009 22:55:48 »
Sh* :::)))

A boar?

And thinking of your wife is nice. Myself I usually wonder (Worry!!) about my bike ::))
But I can see that your wife might want a word about it :)

You destroyed my theory here ::))

I always thought that if you thought about anything else than your bike it was time to stop driving. But a wife waiting for you to explain why you and that bear had such an intimate relation ::))

As they say, we bikers are a hardy species...
 

Offline geo driver

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Why can't I see at night?
« Reply #19 on: 12/12/2009 22:58:14 »
Wellllllll  to tell the truth i though my wife would be angry at teh expence of getting 2 new front forks for the bike... the bill for the repares you see
 

Offline geo driver

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Why can't I see at night?
« Reply #20 on: 12/12/2009 23:00:19 »
and for the first time in my life i saw a pig fly... i diddent even fall off back wheel of the ground and and nearly fell but stayed on like a trooper.  1 side of the bike covered in pig s*** the other side in bacon it stank
 

Offline yor_on

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Why can't I see at night?
« Reply #21 on: 12/12/2009 23:03:50 »
You're the lucky one, a wealthy independent wife that repairs your bike:)
Does she have a sister?

Yeah I've been in some too, one in India where a water buffalo took me with its horn in the side and me cannoning on the tarmac riding on my little round metallic box of snuff inside my pocket with an Indian hitchhiker riding on my back. We must have looked quite funny ::))

Bacon huh?

---
I'm still nerve dead where that box was :)
 

Offline geo driver

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Why can't I see at night?
« Reply #22 on: 12/12/2009 23:07:21 »
harsh buddy but hay every time you fall off you get better and better at it
 

Offline yor_on

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Why can't I see at night?
« Reply #23 on: 12/12/2009 23:09:58 »
Yep, I can proudly say that my falling off is 'state of the art' nowadays ::))
 

Offline yor_on

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Why can't I see at night?
« Reply #24 on: 12/12/2009 23:12:29 »
I loved the one with the bear man..

 And the bacon was nice too ::))

It's like they say.. It's not the pain, it's the memories that makes it worthwhile :)
 

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Why can't I see at night?
« Reply #24 on: 12/12/2009 23:12:29 »

 

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