A positive afterimage occurs when you look at a bright object for a period and then shift your gaze to a neutral background. Instead of seeing a dark silhouette, you perceive a lingering image that retains the same colors and brightness as the original object. This phenomenon happens because the photoreceptors in your eyes continue to send signals to your brain even after the stimulus is removed. This effect is different from a negative afterimage, where the colors are inverted. Positive afterimages are often brief and fade quickly, but they can be more pronounced with high-contrast images. Understanding this visual effect can help in studying how the human visual system processes light and color.