Which can you seen in this optical illusion, a duck or a bunny? Perhaps you can see both, simultaneously. The duck is facing one way, with its bill slightly open. The bill is also the bunny’s ears.
This type of illusion was first used in the early 1900s by a psychologist called Joseph Jastrow. He created this illusion to show that what we see is not just because of stimulus, but also because of the mind – that we see with our minds as well as our eyes. Jastrow originally found a similar image in Harper’s Weekly and created his own.