This is perhaps the most well known optical illusion, which was first made popular in the 1900s. It remains simple but effective to this day. As soon as it appears, the spiral will rotate endlessly, moving outwards and moving inwards in circles. When you look away from the screen, the spiral will continue to move.
Stare at its centre for around a minute (wait until it has loaded properly first). Then look away from the screen and stare at the back of your hand. See if it begins twitching and moving! The effect is like bugs crawling beneath the skin.
The Skin-Crawling Spiral
Please wait a moment until the spiral has finished loading.
When it's spinning smoothly, stare at the center of the spiral
for about a minute. Then look at the back of your hand...
It will appear to be twitching and moving, as though
bugs were crawling under your skin!
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