An intelligence quotient (IQ) is a total score derived from a set of standardised tests or subtests designed to assess human intelligence. Researchers have been studying the effects of optical illusions on the human brain for many years, and they have created a number of studies that show how various areas of the brain react to optical illusions.
Put your ability to observe things to the test right now. Optical illusions are fascinating visual phenomena that trick our brain into perceiving something that is not actually there or interpreting something differently than it actually is.