Is this an eye or a draining sink? If you're schizophrenic, you might not be fooled by optical illusions. Find out why

Optical illusions are tricks that often exploit the way our minds process images. One of these is the ‘hollow mask’ illusion where the concave side of a mask appears as the convex side. Not everyone falls for these, however. People with schizophrenia see the image for what it really is.

Most people are fooled by this illusion because the mind has what can be thought of as stock images which it uses to make sense of what it sees. When an image looks familiar, there is an interaction between what is there and what we expect to be there and our mind combines these to form the final image that you see. In some cases the expectation can overpower the light coming into our eyes and make us see something differently than what is really there.

People with schizophrenia don’t have this interaction between expectation and reality in their brains. They see what is really there by picking up on shadows or other cues to see a concave image without having these “stock” photos to overpower them. Drunk and high people have been known to “beat” the illusion as well, which means that these drugs also create a disconnect between expectations and reality.

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