Amazing Illusions

GigglePEDIA Welcome to the archive of optical illusions to challenge your mind. Many of the images you will find here demonstrate visual phenomena, and optical or visual illusions. You will learn about the complexities of the human eye first hand. Open any optical illusions below and give your eyes and brain the time of their lives!
Brain conflict
Read the colors, not the words.

Left-Right Conflict
Your right brain tries to say the color and your left brain insists on reading the word
brain conflict

circle or not

Circles or spirals


count the dots


face on mars

find the 13 faces

find the baby

See next picture
how is this possible

The reason that people sometimes find this puzzling is because they start off making an assumption. Often they don`t even realise they have made this assumption. The assumption is that we are comparing two triangles, and that they each have the same area. Certainly a quick inspection - helped by the grid - is that the `triangles` are 13 squares across, and five squares high, and they kind of look the same.

In fact the top triangle is not a triangle at all, it is a quadrilateral. If you look closely along the line of the hypotenuse (the diagonal), you will see that it is not quite straight, it is slightly concave. Why? Well, the dark green triangle is 5 squares across, and 2 squares high. The red triangle is 3 squares high, and should be 7.5 squares across for the hypotenuse to have the same angle to the horizontal. In fact the red triangle is 8 squares across, and the angle of the hypotenuse is slightly shallower that that of the green triangle. Which is why the hypotenuse is not a straight line, when you look closely.

The bottom `triangle` is not a triangle either, it is also a quadrilateral, but now the hypotenuse is slightly convex, since the position of the red and green triangles is now reversed.

Here is an image of the two triangles superimposed, which shows the difference in the two hypotenuse...
how is this possible_1

how many legs

impossible illusion

magic circle

moving circles

Moving dots


parallel or not

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