näköesteitä
Näköesteitä, also known as "visual illusions," are optical phenomena that trick the human visual system into perceiving something that is not actually present or that is distorted. These illusions can be categorized into several types based on their underlying mechanisms. One common type is the "geometrical illusion," which involves the perception of shapes and sizes. For example, the Müller-Lyer illusion creates the illusion of different lengths for two parallel lines, even though they are actually the same length. Another type is the "ambiguous figure," where the same set of visual elements can be perceived in two or more different ways. The Necker cube is a well-known example of this, where the cube can be seen as tilting in either of two directions. "Color illusions" manipulate the perception of color, such as the simultaneous contrast illusion, where a gray square appears differently colored when placed next to differently colored squares. "Motion illusions" involve the perception of movement, like the rotating snake illusion, where a stationary image appears to move. "Depth illusions" affect the perception of three-dimensional space, such as the Ponzo illusion, where two lines of equal length appear to be different lengths due to the surrounding context. These illusions are not merely curiosities but are also studied in psychology and neuroscience to understand the workings of the human visual system.