A fun trick to see the vasculature of your eye

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Discussion Overview

The discussion revolves around a technique to visualize the blood vessels in the eye, often referred to as the "pinhole trick." Participants share their experiences, techniques, and observations regarding this method, exploring its effectiveness and variations in perception. The scope includes personal anecdotes, experimental attempts, and references to historical figures in optics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants describe a video that explains the trick and express their excitement about it.
  • Several individuals share personal techniques, such as using a finger pinhole or different aperture sizes, to see the vasculature.
  • Some participants report success in seeing the blood vessels, while others express frustration at not being able to see anything.
  • There are discussions about how the visibility of the vessels may depend on factors like lighting conditions and individual eye conditions, such as astigmatism or myopia.
  • Some participants describe the patterns they see, comparing them to eye floaters or other visual phenomena.
  • There are mentions of historical experiments by Isaac Newton related to vision and perception.
  • Participants discuss the importance of movement and the size of the pinhole in achieving the desired effect.
  • Some express curiosity about the relationship between their vision conditions (e.g., needing glasses) and the ability to see the vasculature.

Areas of Agreement / Disagreement

Participants generally do not reach a consensus on the effectiveness of the technique, with multiple competing views on its success and the factors influencing visibility. Some report success while others do not, indicating a lack of agreement on the method's reliability.

Contextual Notes

Participants note that individual eye conditions, such as astigmatism and myopia, may affect the results, but there is no definitive conclusion on how these factors influence the ability to see the blood vessels. The discussion also highlights the variability in personal experiences with the technique.

Who May Find This Useful

Individuals interested in optical phenomena, vision science, or those looking for experimental techniques to explore their own vision may find this discussion relevant.

KingNothing
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In this video, the narrator explains why you aren't normally able to see the network of blood vessels in front of your eye, and a neat trick to actually see it. I thought it was really cool.

http://www.youtube.com/watch?v=L_W-IXqoxHA&t=3m8s
 
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KingNothing said:
In this video, the narrator explains why you aren't normally able to see the network of blood vessels in front of your eye, and a neat trick to actually see it. I thought it was really cool.

http://www.youtube.com/watch?v=L_W-IXqoxHA&t=3m8s

Haha, very cool. Ever since college I've been using the finger pinhole technique as a lens when I can't quite see something, but didn't know about this one.
 
Isaac Newton experimented with his own eyes to the point where he could have been blinded.

He would take a narrow dowel and probe near the back of his eye to produce black spots (seemingly opposite to where he was prodding). Part of his "Opticks" research?

I believe all of us have done this to some degree.
 
Loren Booda said:
I believe all of us have done this to some degree.

Snorting high voltage, yes, but never a poke in the eye. That's nuts!
 
Whoa, it works!
 
Trying for 5 minutes on different surfaces (white paper, white wall, white board) under a lightbulb, I see nothing special. :/
 
fluidistic said:
Trying for 5 minutes on different surfaces (white paper, white wall, white board) under a lightbulb, I see nothing special. :/

I think it works best if you have all the other light blocked out so you're only seeing through a tiny hole. I made the hole in an old hockey ticket, about 1mm in diameter. Try the white background on a computer screen.
 
Not working for me either... guess I'm not normal. <sigh>
 
  • #10
How is it supposed to look like? Like eye floaters? If so, since I suffer from myodesopsia this might explain why I don't notice anything.
 
  • #11
fluidistic said:
How is it supposed to look like? Like eye floaters? If so, since I suffer from myodesopsia this might explain why I don't notice anything.

I see a faint pattern of squiggly lines around the center of my field of vision. It is subtle but clearly there.
 
  • #12
The trick is to
1] aim at a bright source. I'm using a fluorescent ceiling panel.
2] make your movements smaller than the size of the pinhole. So, my pinhole is 1mm, I'm making my movements <1mm.

What isn't clarified is how far from your eye you hold the card, but I'm doing about 3".
 
  • #13
fluidistic said:
How is it supposed to look like? Like eye floaters? If so, since I suffer from myodesopsia this might explain why I don't notice anything.
Kinda like eye floaters but squiggly lines.
 
  • #14
I would call the image I see a "diffraction pattern."
 
  • #15
I'm seeing something, I guess it must be it. I use my hands and 1x0.3 cm wide opening approximately. I move the aperture probably a bit more than its size. When I use smaller apertures I see the same thing but light has less intensity due to diffraction I think so a huge aperture works fine. Even a 1x1 cm aperture work although better around the edges.
I wish the brain would stop to "see" eye floaters too.
 
  • #16
Wow that's awesome. I did it and I could see a textured relief-like image very clearly - you can even kind of follow the pattern by turning your head a little so the light is coming in at slightly different angles.
 
  • #17
doesn't work for me, I think to too severely astigmatic and myopic
 
  • #18
This explains what I've been seeing. It looks like a rosette where only the wavy tips of the open rose are traced in a light gray. I see that every day.
 
  • #19
wukunlin said:
doesn't work for me, I think to too severely astigmatic and myopic

I think it shouldn't matter, it is not about where the light is getting focused.
 
  • #20
Oh wow, that is awesome. I don't know if it is because I am very farsighted, or if that doesn't matter, but I immediately see the entire network of vessels. ; I could draw a complete map if I needed to.
 
  • #21
Still can't see it. I wonder if it has anything to do with my needing glasses to see anything up close?
 
  • #22
Q_Goest said:
Still can't see it. I wonder if it has anything to do with my needing glasses to see anything up close?

It shouldn't. It's occurring independent of the focus. i.e. it's equivalent to placing objects directly on an unexposed film under a light.
 
  • #23
DaveC426913 said:
It shouldn't. It's occurring independent of the focus. i.e. it's equivalent to placing objects directly on an unexposed film under a light.

That was my conclusion also; anyway, I'm extremely far-sighted (near point is 50 feet), and I saw the vasculature immediately. Bright back light & not too tiny pinhole. The fingle-pinhole he demonstrates works well. I rested my finger knuckle on my forehead and moved it as though I was massaging my eyebrow. Making circles not-as-big as the aperture is key.
 
  • #24
Chi Meson said:
That was my conclusion also; anyway, I'm extremely far-sighted (near point is 50 feet), and I saw the vasculature immediately. Bright back light & not too tiny pinhole. The fingle-pinhole he demonstrates works well. I rested my finger knuckle on my forehead and moved it as though I was massaging my eyebrow. Making circles not-as-big as the aperture is key.
hmmm, I'll try again some other time.

I remember once I had a major greyout just before my vision was completely gone (temporarily) I was seeing lines like tree roots in my field of vision. Could that be the same thing?
 
  • #25
Tree roots is not a bad description of the vasculature looks like.

Note: glasses shouldn't mean anything, I guess you will get correct results without glasses. As I said before, it is not about where the light is focused, it is about shadows dropped by the veins that are almost touching the retina.
 
  • #26
Is the pattern like that of the retina from an ophthalmologist's light?
 
  • #27
Loren Booda said:
Is the pattern like that of the retina from an ophthalmologist's light?

Yes.
 

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