This link:How Many Circles Can You See In This Optical Illusion? | HuffPost UK Tech contains a picture and asks how many circles can you see. I think I could stare at that picture from now until the end of the week and still not see any circles. Not only aren’t there any curved lines in it, there are no oblique lines. Yet they claim that the average person will see it within a minute and will thereafter be unable to unsee it. What about you?
Yeah, I can see the circles. Look at the vertical lines–they form 16 circles of vertical lines.
Yeah, it’s one of those cool illusions where it just suddenly clicks into place. As Lemur866 said, stare at the centers between the “boxes”.
I can unsee them by focusing on the center of one of the boxes, but as soon as my eyes drift, I see circles again.
I read the OP, then I clicked on the link. I looked at the picture and thought “he’s right, there are just rectangles within rectangles. It’s all straight lines, how could there be any… Oh, there they are.”
Which probably doesn’t help, does it?
I had to start looking for curves, which meant I started looking for diagonals. As soon as I looked at the intersection of vertical and horizontal lines, I saw a diagonal, then a curve, then everything popped into place. It took me awhile to come up with this approach, though.
Yes. It took me about 8 seconds. It’s sorta like one of those old, Magic-Eye images.
The boundaries of the circles are the boundary between horizontal-line regions and vertical-line regions. Everywhere where the lines are vertical is inside of a circle; everywhere where the lines are horizontal is outside.
The edges of the circles are not solid lines, so (if you’re still struggling with this), stop looking for curved LINES. There aren’t any. The circles are small–at first I was looking for big circles. The circles are the same height (diameter) as the height of each box. Also, the dark-light differences in the lines aren’t relevant and serve only to confuse the eye.
The first time, I couldn’t see the circles no matter how I tried to view it, even looking for clues. Reloaded the page and the circles popped out .
I can both see and unsee the circles. I have magic eyes.
Now I can’t unsee the circles.
No soap, radio.
When the picture finally rendered I instantly could see the circles in the top row but not in the lower rows. Then each row started oscillating in and out of view. Very odd sensation. But it was always per-row, never per-column.
It’s now been a couple minutes since I looked at the pic. Let’s see what happens when I switch windows …
I’ve learned that if I look at the “boxes” then the circles disappear in that row and the adjacent rows. But if I look explicitly at the long uninterrupted horizontal lines between the rows of boxes then the circles leap out at me.
I suspect that part of the illusion is the complicated vertical line patterns give your horizontal vergence system fits.
When you focus just on the uninterrupted horizontal lines your (=my) eyes lose their left/right lock-on cues and go slightly cross-eyed or spread-eyed. At which point the carefully designed vertical sections jump into their circle configuration in your near-peripheral vision.
When you focus on the layer above or below the uninterrupted horizontal layer, i.e. where there’s a mix of horizontal and vertical lines, then the two-eye tracking system has better reference points and the box shapes snap back into view.
Or something. 
All in all this is a new illusion to me and a fun one.
Hmm, the image is rotated, and the circles drawn on don’t match the ones we’re looking for (the drawn outlines are a bit larger). I think it’s actually harder to see the circles here, especially the ones enclosed by the drawn outlines.
That is one very cool optical illusion. There are so many floating about the web that are just “meh.” This is one of the better ones, IMO.
It might not help anyone but I saw the circles by telling myself not to see the images as “door panels with 3D depth” but as a flat image. Worked for me.
I see and unsee them, but not really at will. It just seems to happen as my eyes change focus.
The little extra dots at the corners gave me a hint but it still took a while to spot any circles. They don’t stay there for me for very long, I can’t see all 16 at once.
I was unable to see the circles at all until I saw this image. Now if I look at the areas of the image in which the circles are not indicated by the white circles, I still can’t see them. Only by looking inside the white circles and then transferring my gaze can I make the circles pop out.
Bingo, ThelmaLou. As soon as I read your post I was able to see them. So the “points” of the circle are the corners of the squares. Thanks.