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Author Topic: Why do I see six lights?  (Read 7256 times)

Offline Geezer

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Why do I see six lights?
« on: 11/12/2009 22:37:24 »
At night, when I'm driving perhaps half a mile behind the car in front, instead of seeing two red tail lights, I see six! Each light appears as three lights arranged in an equilateral triangle pointing up. The first time I saw it it I remember trying to work out what kind of car had such a configuration of lights. As I get closer to the vehicle, its lights converge into a single light.

This effect helped to convince me I didn't only need glasses for reading.

So why do I see three red lights when there is really only one?


 

Offline Chemistry4me

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Why do I see six lights?
« Reply #1 on: 12/12/2009 01:11:33 »
You're not alone, I see four instead of two ;D
 

Offline Bored chemist

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Why do I see six lights?
« Reply #2 on: 12/12/2009 15:15:31 »
Do you have a heated windscreen?
 

Offline RD

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Why do I see six lights?
« Reply #3 on: 12/12/2009 16:38:29 »
Multiple images possibly due to laminated glass windscreen ...

Quote
A typical laminated makeup would be 3 mm glass / 0.38 mm interlayer / 3 mm glass. This gives a final product that would be referred to as 6.38 laminated glass.
http://en.wikipedia.org/wiki/Laminated_glass

The refractive index of the plastic "interlayer" will be close to, but not exactly the same as, that of the glass.


Perhaps in combination with astigmatism ...

Quote
Astigmatism is quite common. Studies have shown that about one in three people suffers from it.
The prevalence of astigmatism increases with age. Although a person may not notice mild astigmatism, higher amounts of astigmatism may cause blurry vision, squinting, asthenopia, fatigue, or headaches.
http://en.wikipedia.org/wiki/Astigmatism#Ophthalmic_astigmatism
« Last Edit: 12/12/2009 16:49:00 by RD »
 

Offline Geezer

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Why do I see six lights?
« Reply #4 on: 12/12/2009 18:26:13 »
No heated windscreen. My glasses do seem to make it go away, so I suppose it may be some sort of astigmatism, although I think they are only correcting my inability to focus, even at infinity!

We have one of those seven segment display alarm clocks with red LEDs. Without my glasses it looks like complete jumble of segments. Red light seems to accentuate the phenomenon.
« Last Edit: 12/12/2009 18:30:08 by Geezer »
 

Offline Chemistry4me

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Why do I see six lights?
« Reply #5 on: 13/12/2009 05:10:47 »
So why do I see three red lights when there is really only one?
You've got light hitting your retinas all funny, so there are 3 lights instead of one



http://en.wikipedia.org/wiki/File:Myopia.svg

 

Offline Geezer

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Why do I see six lights?
« Reply #6 on: 13/12/2009 05:27:05 »
So why do I see three red lights when there is really only one?
You've got light hitting your retinas all funny, so there are 3 lights instead of one



http://en.wikipedia.org/wiki/File:Myopia.svg



Well yes, if there are three sources of light as shown in the diagram. But isn't there only one?
 

Offline Chemistry4me

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Why do I see six lights?
« Reply #7 on: 13/12/2009 05:36:55 »
That is just a simplified diagram showing three rays from an object, not three sources, in reality there will be many many more.
 

Offline Geezer

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Why do I see six lights?
« Reply #8 on: 13/12/2009 05:50:00 »
I agree. So why would I see three points rather than a blur?
 

Offline Chemistry4me

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Why do I see six lights?
« Reply #9 on: 13/12/2009 05:55:48 »
Uh...beats me [:I]
 

Offline Geezer

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Why do I see six lights?
« Reply #10 on: 13/12/2009 06:04:03 »
Dang chemists. All they ever do is balance stuff.
 

Offline Chemistry4me

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Why do I see six lights?
« Reply #11 on: 13/12/2009 06:09:36 »
Do you really see 3 clear lights or is it kind of like 3 blurred ones where you can't make out the edges?
 

Offline Geezer

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Why do I see six lights?
« Reply #12 on: 13/12/2009 06:24:34 »
Three lights. No kidding. Although I must confess this was some time ago. I should try to repeat the "experiment" but my eyes may have changed in the meantime.
 

Offline Chemistry4me

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Why do I see six lights?
« Reply #13 on: 13/12/2009 06:46:28 »
I should try to repeat the "experiment" but my eyes may have changed in the meantime.
You might see 10 instead of 6!
 

Offline Geezer

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Why do I see six lights?
« Reply #14 on: 13/12/2009 06:49:34 »
I'll give it a shot and report back  :D
 

Offline Chemistry4me

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Why do I see six lights?
« Reply #15 on: 13/12/2009 06:51:10 »
Just not too many shots or else you won't be fit to drive.
 

Offline Geezer

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Why do I see six lights?
« Reply #16 on: 13/12/2009 06:57:21 »
No problem. That's why they allow us to have automatic rifles here.

(Sh*t! I can't believe I just said that. Sounds like something JimBob would have said.)
 

Offline Chemistry4me

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Why do I see six lights?
« Reply #17 on: 13/12/2009 08:12:27 »
I didn't mean that kind of shot...

 

Offline Geezer

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Why do I see six lights?
« Reply #18 on: 13/12/2009 21:19:06 »
I didn't mean that kind of shot...



Oh...(thinking)...............OK, you mean like flu shots?
 

Offline Chemistry4me

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Why do I see six lights?
« Reply #19 on: 13/12/2009 21:28:53 »
A shot glass is a small glass designed to hold or measure liquor

http://en.wikipedia.org/wiki/Shot_glass

That kinda shot :)
 

Offline Geezer

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Why do I see six lights?
« Reply #20 on: 14/12/2009 03:44:39 »
Oh! That kind of shot. I usually have a couple if Mrs G is going to be doing the driving.

(That's not really true. Mrs G is a good driver.)
 

Offline geo driver

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Why do I see six lights?
« Reply #21 on: 14/12/2009 11:29:48 »
could it just be that squinting and focusing on a point a long way away makes you go cross eyed.
 

Offline Geezer

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Why do I see six lights?
« Reply #22 on: 14/12/2009 20:26:21 »
Well, I may be cross eyed, but I see the effect with either eye when the other is covered.
 

Offline Fozzie

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Why do I see six lights?
« Reply #23 on: 17/12/2009 12:37:39 »
You may be suffering from a dystrophy of the cornea where the smooth surface develops little bumps on it, each acting as an individual lens splitting up the image. I know because I have it and the symptoms are exactly as you describe. You can test it yourself by looking at a small red light such as you get on the front of your TV and looking through a pinhole at it. If the multiple images merge into one, it's corneal dystrophy. Your optician can confirm this.
 

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Why do I see six lights?
« Reply #23 on: 17/12/2009 12:37:39 »

 

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