👉 Calogram is a type of optical illusion where an object appears to be larger or smaller than it actually is due to the difference in distance between the object and the observer. The term was first used by the British physicist George A. Fritsch in 1920, who observed that when a light source is placed in front of an object, the object appears to be larger than the light source, but as it approaches the observer, the size of the object decreases until it matches the
