Do you see round columns, or square? How does the draughtsman do
Devil's Tuning Fork
Question: Does the rod in the middle really exist?
This perception illusion is often called the 'Devil's Tuning Fork'.
Is this door opening inwards? Or is the top opening out towards us?
3-D Optical Illusion - Beams
One beam seems to disappear in the middle.
An impossible object is a type of optical illusion where your brain
interprets a two dimensional object as though it exists in 3-D, even though
it is not geometrically possible for such an object to actually exist.
3-D Tongue and Groove Optical Illusion
The clever draughtsman has made the 'tongue' disappear.
3-D Classic Rectangle
The father of such impossible optical illusions is Oscar Reutersvärd (1915–2002).
It was he who first drew what would become known as the Penrose Triangle,
Now or a Different Optical Trick
Gaze at the middle one of the circles. That circle stops rotating, but
your periferal vision sees the other circles spinning - eerie.
note: the above whirl image is not animated.
See our collection of
• cool optical illusions.