Blind spot
 

MegaSack DRAW - This year's winner is user - rgwb
We will be in touch

[Closed] Blind spot

16 Posts
8 Users
0 Reactions
131 Views
Posts: 77705
Free Member
Topic starter
 

Think you've got good eyesight? I don't know if this will work embedded here, so bear with me.

Close your left eye, and watch the spot on the left with your right eye.

[img] [/img]

The big dot should hit yor eye's blind spot and disappear. I found the effect more noticeable if I tilted my head left slightly. Try the original if it doesn't quite work:


 
Posted : 13/04/2012 10:57 pm
Posts: 0
Free Member
 

Yep - works for me. Isn't that when image of the spot passes some optical nerve at the back of your eye. I recall something similar in a comic many, many years ago 🙂


 
Posted : 13/04/2012 11:00 pm
Posts: 0
Free Member
 

Ooh!, That's quite freaky!


 
Posted : 13/04/2012 11:02 pm
Posts: 77705
Free Member
Topic starter
 

Yeah, that's exactly what it is, it's where the optic nerve head joins the retina.

Odd that we never notice. Normally the eyes compensate for each other, but even with one eye closed it's still hard to tell there's something missing.

Try the same trick with the moon; now that is freaky.


 
Posted : 13/04/2012 11:03 pm
Posts: 5559
Free Member
 

well it works embedded but as i can only see out my right eye I am not sure what is meant to happen but it was nothing for me and nothing going to the link
I am probably not a great test subject

EDIT: I seem to natural flick out my eye as it hits the blind spot which may be something I have learnt to do automatically as I am monocular???


 
Posted : 13/04/2012 11:03 pm
Posts: 0
Free Member
 

The place at which it disappears varies according to how close to the screen you are. The closer you are, the nearer to the little dot.

I think we don't normally notice it because our eyes actually move around a lot, so our brain constantly fills in the missing information.


 
Posted : 13/04/2012 11:06 pm
Posts: 77705
Free Member
Topic starter
 

Junky > shouldn't matter - the physiology of your good eye is still the same. Try moving closer to the screen.


 
Posted : 13/04/2012 11:07 pm
Posts: 77705
Free Member
Topic starter
 

EDIT: I seem to natural flick out my eye as it hits the blind spot which may be something I have learnt to do automatically as I am monocular???

Really? Wow, now that is interesting. You're [i]subconsciously [/i]compensating?


 
Posted : 13/04/2012 11:08 pm
Posts: 4
Free Member
 

It's amazing that by concentrating so hard on the spot, that you miss the dancing bears that appear momentarily !


 
Posted : 13/04/2012 11:12 pm
Posts: 77705
Free Member
Topic starter
 

Shush, you'll ruin it for everyone!


 
Posted : 13/04/2012 11:34 pm
Posts: 1827
Free Member
 

Does anyone else find the spot doesn't disappear completely, but flickers for the furthest part of its path?

Edit: Also It only works for me when I click on the link. Think the embedded version is too small.

Edit2: I have been looking at it for a while and I think its flickering after it disappears as if it is coming back into view again. So rather than having an edge to my vision. Its a spot near to the edge.


 
Posted : 13/04/2012 11:41 pm
Posts: 0
Free Member
 

Thanks for the tip - I shall now never look to the left with my right eye and my head slightly tilted, in case someone creeps up on me.

You can't be too careful round these parts.


 
Posted : 13/04/2012 11:45 pm
Posts: 77705
Free Member
Topic starter
 

Chris > move closer / tilt your head?


 
Posted : 13/04/2012 11:48 pm
Posts: 5559
Free Member
 

Must do as I had never noticed it before but yes I do do this.

i do some stuff i notice , never turn turn to the left as I cannot see for example


 
Posted : 13/04/2012 11:52 pm
Posts: 0
Free Member
 

Stick a wee hole in piece of paper. Look through it at arms length at a distant object.

Bring the paper right up to your face still looking at the object.

Now wink. Whichever eye you can still see out of is your dominant eye.


 
Posted : 13/04/2012 11:56 pm
Posts: 77705
Free Member
Topic starter
 

Yup. Archers do that to work out which hand to shoot.


 
Posted : 14/04/2012 12:06 am
Posts: 1827
Free Member
 

Stick a wee hole in piece of paper. Look through it at arms length at a distant object.

Bring the paper right up to your face still looking at the object.

Now wink. Whichever eye you can still see out of is your dominant eye.

Much easier way of doing that...

Make a circle with your hands.
Put at arms length.
With both eyes open, pick something and position it in the middle, then close one of your eyes, then the other. One of your eyes will have the object appear in the middle, the other at the edge.
The side open when the object is in the middle is your dominant eye.


 
Posted : 14/04/2012 12:34 am