Well, can you? ~ Page 1

Which red circle is bigger?

The Lipps Illusion ~ 1897

Are the red lines curved?

Is that a square and a circle?

Are you certain you can see a spiral?

What about this one ? A spiral or concentric circles ? Sure ?

Are you seeing spots before the eyes yet? - The Hermann Grid

The intersection you look at won't change colour, but the others will !!

A variation of the Hermann Grid

What about the stripes in the circles? Sure?

What is going on here?

Thiery's figure

The Z?lner Illusion - The longer lines really are parallel!

How many triangles can you see in each of these 4 pictures

1, 2 or none?

If you see an upside-down triangle in these pictures, what happens to its shape in the bottom right picture?

Kanizsa figures

M?ler-Lyer Illusion - are the long lines the same length?

What about the two red lines in this image?

Look at the black centre of this image.

What happens to the grey area surrounding it ?

Look at the bulb for 30 seconds, then at the white area to the right.

The bulb will switch itself on!

Look at this image for 5 seconds, close your eyes and look at the white area

How many shades of pink are there in this picture ?

In fact there is only one!

What about this pair of lines?

And this pair of thick lines?

First noted by Mario Ponzo in 1913

Perspective Distortion

The further the figure gets from us the bigger he gets?

Necker Cube ~ 1832

Which face is nearer to you?

Ponzo Illusion

Which circle is bigger? or are they the same size?

Poggendorff Illusion

Would the inclined line make a single straight line?

Orbison Variant

Are these true circles?

Another Orbison variant - is this really a circle ?

Lipps Variant A

What is that diamond doing to that circle?

Lipps Variant B

What are the arcs doing to the circle?

Are the shades of grey different or the same?

Which of these two shapes is the larger?

The figure in the circles is actually square.

This page created 3rd June 1999, last modified 19th October 2005