Okay, there is an illusion known as the "hollow face" illusion where you look at a rotating mask that is concave on one side. Most people apparently are typically not able to see through the illusion, but those with schizophrenia are able to see through it. Also, those with exceptionally high levels of intelligence are able to see through it. Well, anyways I was able to see through it easily. Apparently, around 90% of people aren't able to see through it.