Well, can you?
Which red circle is bigger?
The Lipps Illusion ~ 1897
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
How many black dots are there?
A variation of the Hermann Grid
What happens when you stare at the center of this image?
What about the stripes in the circles? Sure?
What is going on here?
Thiery's figure
The Zollner 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
Twisted Cord Illusions
The false spiral or twisted cord illusions were first described by psychologist Sir James Fraser (1863-1936) in 1908 when he was Deputy Medical Superintendent of the Central London Sick Asylum. He described the illusion in a paper, A new visual illusion of direction, in the British Journal of Psychology; Volume 2, Issue 3, (Jan 1, 1908).
THe illusion is produced by combining a regular line pattern (the circles) with misaligned parts (the differently colored strands). A sequence of tilted elements causes the eye to perceive phantom twists and deviations
James Fraser's Twisted Cord illusion
Life ~ Another of James Frasers twisted cord illusions
Are the letters really crooked?
Twisted cord illusion
Are you certain you can see a spiral?
What about this one ? A spiral or concentric circles ? Sure ?