What Do You See First? The Optical Illusion That Has Everyone Looking Twice

demonstrate that vision is not simply about what enters our eyes—it is also about how our brains interpret that information.

Scientists have studied visual perception for decades and have discovered that our expectations strongly influence what we see. When presented with

incomplete information, the brain fills in the gaps using past experiences. This process is usually helpful, but illusions reveal the occasional errors that result.

Psychologists also find optical illusions useful because they provide insight into attention and