Cool Optical Effect

[xSilverPhinx]

Which direction are they going? Slowly look around the picture (light to darker spots), and you'll see that they seem to switch direction.

[Ecurb Noselrub]

I can get them to go into the light, but the default position for me seems to be that they are coming out.  I can maintain the illusion for awhile but then they switch and go back to the default-exit direction.

[McQ]

I can get them to go into the light, but the default position for me seems to be that they are coming out.  I can maintain the illusion for awhile but then they switch and go back to the default-exit direction.

Same here.

[Amicale]

I can get them to go into the light, but the default position for me seems to be that they are coming out.  I can maintain the illusion for awhile but then they switch and go back to the default-exit direction.

Same here.

Same with me, I can make them go in, but my brain automatically flips it to them coming out.

[xSilverPhinx]

Looks like it has something to do more with perephrial vision than staring at the light spot to make it go in. I find these illusions fascinating.

[Hector Valdez]

There's a sweet spot juuust above the opening of the whole that keeps them fat suckers going in all night long...

[OldGit]

This one's fun, too, bit I like the bubbles better.

[Amicale]

This one's fun, too, bit I like the bubbles better.

Whenever I see that one, I always see it going counterclockwise (to the left) at first, and I have to force myself to see it spinning clockwise (to the right). Anyone else predominantly see it the opposite way?

[hismikeness]

I can't get the spinning girl to go clockwise, only counter.  ???

[Space Pope Approved]

Weird...the bubbles only go in for me when I look at the top right corner, and then only after I've moved my gaze along the top of the picture.

And the spinning woman I've only ever seen spin clockwise, but when I looked at the image in Amicale's reply, she spontaneously started spinning counterclockwise!  Then after about 10 seconds she switched back.  I can't make it happen consciously though. 

[DeterminedJuliet]

I can't get the spinning girl to go clockwise, only counter.  ???

That's what happened when I first looked at her and then I looked at her foot at the bottom. And then she switched. Now I can't get her to go back.
Our brains do weird stuff. Crazy.
Edit: After a bit of practice I can now switch back and forth between her going right and going left, but I need to glance at her foot to make her "switch". Cool.

[Ecurb Noselrub]

I can't get the spinning girl to go clockwise, only counter.  ???

Focus on the foot touching the ground and imagine it going clockwise.  That allowed me to turn the whole girl (wish that worked in real life).

[Ali]

I can only get her to go clockwise.  My stubborn brain insists that her foot is pointing clockwise, and there is simply no way she could do otherwise.

[Crow]

  They don't work for me. The bubbles/balls are always moving away from the light and the female figure is always spinning clockwise. Tried everything nothing changes.

[DeterminedJuliet]

They don't work for me. The bubbles/balls are always moving away from the light and the female figure is always spinning clockwise. Tried everything nothing changes.

As you look at her bottom foot, just try to be aware of the fact that you can't actually see any depth. Your brain is telling you that at any given point her heel is behind her toe, or her toes are behind her heel, but that's not what you're actually seeing. When you follow her foot around, try to imagine the opposite of what your brain is telling you - when you think her toes are pointing towards you, try to imagine they're pointing away. That's what I did and I eventually got it.