A fun trick to see the vasculature of your eye!

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
 

Ivan Seeking

Staff Emeritus
Science Advisor
Gold Member
7,093
173
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.
 
3,073
3
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.
 

Ivan Seeking

Staff Emeritus
Science Advisor
Gold Member
7,093
173
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!
 

Borek

Mentor
28,013
2,518
Whoa, it works!
 

fluidistic

Gold Member
3,605
90
Trying for 5 minutes on different surfaces (white paper, white wall, white board) under a lightbulb, I see nothing special. :/
 
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.
 

Q_Goest

Science Advisor
Homework Helper
Gold Member
2,973
39
Not working for me either... guess I'm not normal. <sigh>
 

fluidistic

Gold Member
3,605
90
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.
 

Ivan Seeking

Staff Emeritus
Science Advisor
Gold Member
7,093
173
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.
 

DaveC426913

Gold Member
18,149
1,724
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".
 

DaveC426913

Gold Member
18,149
1,724
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.
 
3,073
3
I would call the image I see a "diffraction pattern."
 

fluidistic

Gold Member
3,605
90
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.
 
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.
 

wukunlin

Gold Member
396
44
doesn't work for me, I think to too severely astigmatic and myopic
 

Evo

Mentor
22,860
2,336
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.
 

Borek

Mentor
28,013
2,518
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.
 

Chi Meson

Science Advisor
Homework Helper
1,767
10
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.
 

Q_Goest

Science Advisor
Homework Helper
Gold Member
2,973
39
Still can't see it. I wonder if it has anything to do with my needing glasses to see anything up close?
 

DaveC426913

Gold Member
18,149
1,724
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.
 

Chi Meson

Science Advisor
Homework Helper
1,767
10
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.
 

wukunlin

Gold Member
396
44
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?
 

Borek

Mentor
28,013
2,518
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.
 

Related Threads for: A fun trick to see the vasculature of your eye!

  • Posted
Replies
17
Views
3K
  • Posted
2
Replies
31
Views
3K
A
Replies
15
Views
2K
Replies
37
Views
3K
  • Posted
2
Replies
44
Views
9K

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving

Hot Threads

Top