1.
Stare at the black cross and see the blank space transform into a green dot.
2.
Move your eyes above this line and the black and white dots will look like they're rotating clockwise.
3.
Keep looking at the flashing green dot and the yellow ones will disappear.
4.
Fix your eyes on this black dot and the grey stripe will turn blue.
5.
Watch dark bands appear as these concentric circles pass over each other
6.
These still images start moving once a grating is passed over them.
7.
Look, even this cat sees it.
8.
This is a Penrose triangle, also known as the impossible triangle because how does it work?!
9.
Well, this makes it much clearer...
11.
These three cars are different sizes, right?
Nope, they're all the same.
12.
Which way is this train going?
13.
These yellow and blue blocks look like they're stepping alternately over the stripes.
14.
These blue lines look like they're moving in pairs.
15.
Where does the extra square in this triangle go?
16.
Look at this black dot and see the outlines filled in with colour.
17.
Finally, watch this for a minute or two, then look away.
