Physiological illusions occur when the brain interprets visual stimuli in a way that differs from reality due to the way our sensory systems function. These illusions often arise from the overstimulation of certain visual receptors, leading to effects such as afterimages or color shifts. For example, staring at a bright light can create a lingering image when you look away. These illusions highlight the complex relationship between perception and reality, demonstrating how our nervous system processes information. They are distinct from cognitive illusions, which involve higher-level thinking and interpretation. Understanding physiological illusions can provide insights into the workings of human perception.