12 black dots

[ScumOfTheRoad]

https://twitter.com/markoftheD/status/1262321873041457158

This is a good one!  Calling TimC - I bet you are fantastic at this one.

I can get up to three dots by tracking my eyes round the side of a triangle.

[Jaded]

I managed to get 6

[Beardy]

I can see all 12 when scanning, but only 2 when not.

[ElyDave]

8 at once

[ScumOfTheRoad]

I can see all 12 when scanning, but only 2 when not.

I would get down to your local RAF recruiting office sharpish if I were you.

[mrcharly-YHT]

I can see 12 if I cheat and turn my head on one side (i.e. rotate the image to portrait).

[Cudzoziemiec]

All of them if I stand a couple of feet away. Is that cheating?

[Hot Flatus]

8 at once

[Sergeant Pluck]

8, when about 15cm from the screen. Always either top or bottom half of screen, not the sides.

[Kim]

Paging barakta.  Barakta to the pair of courtesy phones that turn into one if you squint please...

[T42]

Max 4 at once.

[andytheflyer]

Er, what black dots?




(I'll fess up to only one at a time). You lot didn't spend 3 years at uni  looking down a monocular ploarising microscope at thin sections of rocks with your left eye and drawing the crystal structures out on paper with your right eye.
 

Utter cruelty. Bet they don't teach petrology that way now..... (assuming that they teach it at all....)

[Asterix, the former Gaul.]

It's a trick question. I admit nothing without my lawyer.

[TimC]

https://twitter.com/markoftheD/status/1262321873041457158

This is a good one!  Calling TimC - I bet you are fantastic at this one.

I can get up to three dots by tracking my eyes round the side of a triangle.

Just 2. I can see where they all are, but if I hold my eyes steady, just two adjacent ones. I would have thought that seeing more than that means your eyes are wandering, but then I'm not an opthalmiceristiction-type personage. Maybe now I'm officially retired, my eyesight's given up!

Edit: I see the Dr who posted the image says the fewer dots you see, the better your eyesight. That's the kind of upside-down logic I can live with!

[Jurek]

11.

[perpetual dan]

I can see all 12 when scanning, but only 2 when not.

Same. Almost three but they go in and out, and I can get two non-adjacent on a line when I move back a bit.

[Adam]

Edit: I see the Dr who posted the image says the fewer dots you see, the better your eyesight. That's the kind of upside-down logic I can live with!

I can only see 2 at once, and my eyesight isn't particularly good!

[Basil]

Defiantly only one.  Is that a had thing?
I wondered if it was something to do with my varifocals, so I took them off.
Zero.
Doh.

[Wowbagger]

Just two for me. Easy enough to ind them all, but try as I might, I couldn't get to see three at once.

[neilrj]

I get one if I look at any point, 12 (3 rows of 4 ) scanning but I get 24 when scanning when it turns into a stereogram (as in 3d effect not a record player)

What does any answer mean?

[barakta]

Usually 2, occasionally 4.

[Nutbeem]

I get one if I look at any point, 12 (3 rows of 4 ) scanning but I get 24 when scanning when it turns into a stereogram (as in 3d effect not a record player)

What does any answer mean?

I don't think there's an answer as such. I think seeing 2 (or perhaps 4) is physiologically normal, as you look at the screen two of the dots will be focussed on the Fovea (the centre of the Macula) allowing you to see the fine details, the others will be in your peripheral vision which lacks the detail to resolve and see them. It's similar to looking at the page of a book & see lots of words, but reading it requires focussing on each word in turn and scanning along and down through each of the words.

If you scan the image like you would a page of text, then you can quickly identify the location of all 12 dots, but you still can't focus on all of them at the same time.

Another example would be playing MahJong, where you have to identify pairs of tiles. Despite their size and clear differences you need to find one, then scan the screen for a duplicate while remembering where the first tile was located.

[ian]

I see one unless I force my eyes to work together and then I see two.

Given that any given time one of my eyes has wandered off to look at something (honestly, ladies, I am not responsible for it*), I wonder what happens to all the stuff it's seeing. It's bit like the words you type when you've forgot to click on a window on your computer desktop. Bits of me are going elsewhere. Assembling.

I have no depth vision either, and it was consistently hilarious – PE teachers of the world – to throw something at me and shout 'catch.'

*actually, this is a genuine fear, I can be inadvertently staring at someone without knowing.

[ElyDave]

I get one if I look at any point, 12 (3 rows of 4 ) scanning but I get 24 when scanning when it turns into a stereogram (as in 3d effect not a record player)

What does any answer mean?

I don't think there's an answer as such. I think seeing 2 (or perhaps 4) is physiologically normal, as you look at the screen two of the dots will be focussed on the Fovea (the centre of the Macula) allowing you to see the fine details, the others will be in your peripheral vision which lacks the detail to resolve and see them. It's similar to looking at the page of a book & see lots of words, but reading it requires focussing on each word in turn and scanning along and down through each of the words.

If you scan the image like you would a page of text, then you can quickly identify the location of all 12 dots, but you still can't focus on all of them at the same time.

Another example would be playing MahJong, where you have to identify pairs of tiles. Despite their size and clear differences you need to find one, then scan the screen for a duplicate while remembering where the first tile was located.

I can't really say I was focussed on 8 at once, more a 4 in direct vision and 4 in the periphery.  much like your scanning text you need to look directly at them to focus, or the opposite of hidden monsters that dissapear when you look closely

[Jaded]

I would imagine it is less about eyes and more about processing the information. The dots disappear because the brain fills in bits (that don't make sense?) and the bits are nicely filled in with great, because the grey lines should continue, black dots would be an anomaly.