Which of these little guys is the tallest one?

Where did the middle peg come from?

Are the little gray squares the same shade of gray?

Which white bar is longer?

How many circles do you see?

Are the edges of the square straight?

Watch the cube pop back and forth!

Which center dot is bigger?

Is this a duck or a rabbit?

What is this?

Is this a vase? Is it a pair of faces?

Are the short fins near or far away?

Are there grey spots at the intersections?

Which line is longer?

A little something to wake up your eyes...

Stare at the center of this image, then look at a white surface.

Are the longer lines parallel?

Stare at the center of this image, then look at a white surface.

Which of these lines is the longest one?

What does this say?

What does this say?

Do you see an old or a young woman?

Are the two heavy lines straight?

Look twice: what does this REALLY say?

Which inner circle is larger?

Are the holes on the top or the bottom?

Is the ring an even grey?

Is the top or the bottom circle closest?

Stare at the center of this image, then look at a white surface.

Stare at the center of this image, then look at a white surface.

Is this a perfect square?

Which is the lowest step?

Stare at the center of this image, then look at a white surface.

Are the black sides inside or outside?

Stare at the center of this image, then look at a white surface.

Do you see a triangle?