Numerous optical illusions work with constancy phenomena.
- Constancy of form: Objects are always perceived the same from different perspectives in terms of their form. z. B. a rotating coin is always perceived as (circle) round, although its image on the retina is mostly elliptical.
- Size constancy : Objects are always perceived as being the same size at different distances in terms of their size. This plays a role in many perceptual illusions .
- Color constancy: Objects are perceived in an almost unchanged color when the color of the lighting changes , provided that it remains within the range of the natural color changes of daylight .
- Brightness constancy: With different lighting, objects are perceived as being the same in terms of their (color) brightness . Nevertheless, the visual perception is sometimes subject to an interaction, as can be seen in the illustration.
- Orientation constancy: The orientation constancy enables z. B. tilting our head and still perceiving our environment as stable. It comes about through our equilibrium system .
- Phoneme constancy: Phonemes are perceived as identical, although they can be physically formed in different ways.