No, it is simple. In the drawing there are 12 black points. At the same time (and without tension) an eye can see only 2-3 of them. In the center of attention. Other points on the periphery of sight. The brain perceives them as garbage (the mistake in a retina — at us such happens much) and interpolates, deleting "programmatically". As with a blind spot of an eye. When moving a look according to the picture, respectively, a part of points will appear, a part — to disappear.
As I have opened this topic, it is necessary to fill up it Here much more better known and very old optical illusion. I on the Internet have met it in the 1990s. It is necessary to look continuously at a black cross in center during tens of seconds. On this animation a number of violet spots, one of them cyclically disappeared. First look. The mechanism of color compensation works. At flasks of a retina of an eye sensitivity to a certain color decreases if he is visible constantly. An eye sees violet spots and sensitivity to violet falls. When the violet spot disappears, an eye perceives it as a lack of violet. As though violet was absorbed by an objects surface. It looks in the complementary color. In case of violet green. Begins to seem that around violet spots the green spot moves. Further it is more interesting. Violet spots remain in general constants on a uniform background. The brain begins to consider them local distortion of a color rendition of a retina and "corrects an error". Cleans violet spots absolutely. As a result we see how on the gray field the green spot moves.
Here simpler example of color compensation from the previous illusion. Motionless. If to look in a point in the center 20 and more seconds, then color spots will disappear.
It is formally not optical illusion as it is caused not by optical illusion, and the technical reasons stroboscopic effect. But looks beautifully. Unfortunately, I don't know how to insert video on forum that was shown not since the beginning, and since the specified time. So either rewind by 01:32 or click the link.
It is good that in the updated forum engine it is possible to edit old posts I have corrected not working images in old posts.
There has been an illusion nagging at me for a long time. Just the other night I realized what is happening, I think. Where I sit and work, in the extreme peripheral vision of my left eye, I can see a the light from a light outside, illuminating the entry way to the front door. I can't see the light fixture itself, just the light from it. When it starts getting dark out, the light comes on automatically. When it does, I could swear I see the light spread out over the entry way - it seems like I can actually see the motion of the light! That of course is impossible. Light travels at about 300 million meters per second. There is no way I could perceive the movement of the light itself. It has to be some kind of optical effect, but what? I kept thinking it must be a trick of the mind. The other day I remembered an effect where, by using your peripheral vision in motion [ a glancing look], under the right circumstances. you can distinguish certain optical features you can't see by looking directly. It has to do with activating different rods in the eye for each optical feature. And it dawned on me what I think I've been seeing all this time. When the light comes on, the rods in my eye are not activating at the same rate. Rods closer to the center must activate faster than rods at the extreme periphery, so my brain interprets this as motion. It could even be the opposite and for some reason I think the apparent motion is right to left.
Peripheral vision in humans is much more rapid than central. For example, the flickering of the old CRT screen of the TV or display is not noticeable with a direct look, but very noticeable when looking sideways.
Ah! As I said, it could be the opposite. I can perceive motion but its so fast that it's hard to be sure of what I see.
Look, without blinking, in the middle of the image for 20 seconds, and then look at someone's face or just a wall.
Cool stuff!! Seen some of them before. Great thread! Here's an older YouTube video on optical illusitons.....and more... (vSauce)
