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Author Topic: Why does looking at a bright light give you spots before your eyes?  (Read 94890 times)

Offline Chemistry4me

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Offline Chemistry4me

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You wouldn't, by any chance, enjoy a nice swim and boating now and again?
Ah, like those fellows? http://www.specialboatservice.co.uk/
Sounds like they're giving a really good service, although I couldn't for the world find out about their fares?
Well I do enjoy an odd boat and swim around the harbour.
The Special Boat Service certainly looks very attractive.
You know how I am with the Navy/Army. :)
 

Offline chris

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Quick. Someone come and rescue me. Chem4me is making me think I'm a freak. Surely someone has experienced this colour change phenomenon. Anybody?????

This is true - I too have experienced colour changes like this. It's down to retinal processing I think. The retina "tunes" itself to maintain the best visual signal and optimum signal to noise. If the photoreceptors are bleached by intense light (which paradoxically shuts them off rather than turns them on) then there is a compensatory re-tuning effect in the deeper layers of the retina, producing different colour perceptions.

Chris
 

Offline techmind

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I've sure I've posted it before, but here's a cool illusion that'll demonstrate some of the weird stuff the eye/brain does...
http://astarte.csustan.edu/~tom/cool-stuff/
 

Offline John Chapman

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Hi Chris

Thanks for your support


Techmind, that's interesting. That illusion involves generating a green colour in place of the purple. Just as happens with my blotches. That can't be a coincidence. Any idea what the mechanism is?

« Last Edit: 23/02/2009 10:04:14 by John Chapman »
 

Offline yor_on

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Offline Chemistry4me

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Hey I can see the green dots moving if I try hard enough.
 

Offline Chemistry4me

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Are you on drugs?

Nope, on a couch.
Is couch a secret code name for drugs? :)
Btw, that's my drugs couch!
 

Offline yor_on

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Nope no drugs.

Just goodies:)
feature=related

Have a beer on me then, Mr Chem.
(As you already  seems to have taken my couch:)
 

Offline Chemistry4me

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Just goodies:)
What on Earth? Who on Earth?
 

Offline Astronomer_FB

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if i stare at a light bulb for 3 seconds and then look away i see a green bulb next to it for a second or two.  i do know somewhat of what you are talking about, when i was little in elem i would close my eyes and puch them in and i would see black and grey colors forming images and going faster and intensifing. anyone ever done that?
 

Offline Chemistry4me

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Pushing in my eyeballs right now, I can see colours too. :)
There was something about this earlier in this thread.
 

Offline Karen W.

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I see what looks like a green light leading all the pinkish lavender lights around the circle.... like the head of a snake! LOL
 

Offline Dou9las

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Quick. Someone come and rescue me. Chem4me is making me think I'm a freak. Surely someone has experienced this colour change phenominum. Anybody?????
I woke up this a.m. and saw some "after images" without having looked into any bright lights...(scary!!) I found this forum while searching for info.

John, I too see "complimentary" colors with eyes open v. closed, when seeing after images. Just thought I would send you this link also, it appears to be documented as a normal aspect of seeing after images: newbielink:http://www.informaworld.com/smpp/content~content=a791215234~db=all~order=page [nonactive]
Specifically, "In some persons, after-images of images occur in complementary colours."

 

Offline Awesome 2000

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I know im a little bit late but if u still read this i get the exact same thing
With colour changing and things
Exactly as u tell it
 

Offline IamYou

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I found this upon searching for people with similar experiences.  In the animated gif that is in this post when i focus on the center all purple color completely dissapears and I just get left with a green ball that bounces around. 

I've had this happen to me ever since i was a kid.  When I look at light and I close my eyes i see an imprint left.  It's usually purple or green and I can slowly see the color fade away.  I want to use the analogy of a puddle of water slowly evaporating.

(the puddle is the color and spots left in my eye)

Also I believe this is related to the issue of me sneezing when I look at light at certain times of day.
 

Offline dlorde

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If you want to know the details behind how and why you see weird after-image colours, there's a 2005 paper by Paul Churchland called 'Chimerical Colors: Some Phenomenological Predictions from Cognitive Neuroscience', which describes a complete model of human colour vision with enough detail to allow you to predict what colours you'll see under different conditions.

It gets a bit technical in places, but if you're patient, you'll come to a section near the end that shows you how you can see completely new colours that you'll never see normally; these are the chimerical colours of the title, self-luminous colours, and hyperbolic colours.

It's literally an eye-opener, but you'll need a colour-accurate printer to get the best results.
 

Offline yor_on

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A cool read Dlorde. I'm looking forward to read it,
 

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