An optical illusion is a visual phenomenon that tricks the brain into perceiving something that differs from reality. These illusions occur when the brain interprets images in a way that creates a misleading perception of size, shape, color, or motion. They can be created through various techniques, such as contrasting colors, patterns, and perspective. Optical illusions can be categorized into several types, including physiological illusions, cognitive illusions, and literal illusions. Each type engages different aspects of visual processing, leading to unique experiences. Artists and designers often use optical illusions to create engaging works that challenge viewers' perceptions and stimulate curiosity.