These "dots appearing only while (not) focused" are known as "extinction illusions", namely<p><pre><code> "25 - Appearing Dots"
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is "McAnany's type" [1], and<p><pre><code> "26 - Disappearing Dots"
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is known as "Ninio's type" [2], according Akiyoshi Kitaoka's materials. (I have recreated them too few years ago [3][4], before getting to the source.)<p>[1] <a href="https://www.psy.ritsumei.ac.jp/akitaoka/kieru3e.html#:~:text=McAnany%27s%20typeMcAnany" rel="nofollow">https://www.psy.ritsumei.ac.jp/akitaoka/kieru3e.html#:~:text...</a><p>[2] <a href="https://www.psy.ritsumei.ac.jp/akitaoka/kieru3e.html#:~:text=Ninio%27s%20type" rel="nofollow">https://www.psy.ritsumei.ac.jp/akitaoka/kieru3e.html#:~:text...</a><p>[3] <a href="https://codepen.io/myf/full/XjdmJy" rel="nofollow">https://codepen.io/myf/full/XjdmJy</a> ( scintillation warning)<p>[4] <a href="https://codepen.io/myf/full/jMqoMW" rel="nofollow">https://codepen.io/myf/full/jMqoMW</a> ( scintillation warning)
I thought this was going to go the other way.<p>Worked on a project that wanted to make everything a different grayscale color. It was out of control already when someone one day complained that two pieces of text were a different color.<p>They weren’t. They were identical. But they were on two different background colors which make the optical illusion that they weren’t. And I reminded them for the twentieth time that we were using too goddamned much gray.
This coca cola illusion is my favourite one <a href="https://gagadget.com/en/446542-a-photo-of-a-coca-cola-can-that-looks-red-but-is-made-up-of-only-black-and-blue-pixels-is-being-shared-on-social-media-how-does-it-work/" rel="nofollow">https://gagadget.com/en/446542-a-photo-of-a-coca-cola-can-th...</a><p>Coca cola appears red when no red at all is used in whole image
This is a great illusion, though I often see that people try to explain this (and a similar image of strawberries) as "our brain knows this object is supposed to be red so it fills in red", which is not what's happening - it's based on color contrast like many other optical illusions
The background on the can is a very light red. I know from painting murals that a light color close up looks darker from some distance.
This is cool, but more as a demonstration of interesting CSS techniques than optical illusions in my opinion.<p>Also, interestingly, I seem to be able to force myself to "see through" all of these illusions except for induced gradients, which I can't stop seeing unless I cover part of the screen.
Cool!<p>I did something similar for my personal favorite illusion, the Ames window illusion. Recreated with CSS: <a href="https://brandondong.github.io/blog/ames_window/" rel="nofollow">https://brandondong.github.io/blog/ames_window/</a>
33 - color fan: There is another interesting optical illusion here: The fan seems to rotate faster when not directly looking at it.
On #4 (White's Illusion) it looks like for me that the gray bar that is surrounded by black is brighter than the one surrounded by white instead of darker :#
What would be most interesting is using optical illusions to help decode how brain visual processing is done.
These are all super dark, for some reason.
Wow, this is great!<p>I want to put some of them in my UIs.
Heh, I used to do these in Excel.
They could make capchas out of these.