Are these ink blobs or something more?
Click on the picture for more information.
Can you see gray spots in between the black squares?
You see gray spots because your eyes see the black squares but can't make the adjustment to seeing the white lines quick enough. The result is gray, a mixture of black and white.
Which square is the front of the cube?
Do you see the tower on the right side or is the tower on the left side, upside down?
The left tower is pretty easy to see but for those who can not see the right tower here's how.
Treat the bottom square on the right as you would on the left.
Do you see stairs going up or see stairs upside down.
You can probably see the stairs going up but the stairs going down are harder to see. To see the stairs upside down look at the wall behind the stairs and you should seethe stairs upside down. Click the picture if you still can't see the stairs upside down.
Do you see a vase or two people kissing?
To see the vase focus on the black part.
To see the people kissing focus on the white part.
Can you see them?
If you move your head back and forth the circle seems to turn.