Final answer:
The relative size increase phenomenon described is known as the Ames room illusion. It is a trick of perspective that makes objects appear to grow or shrink due to the shape and angles within a specially constructed room, distorting visual perception.
Step-by-step explanation:
The phenomenon where the relative size of a target increases very slowly until it's too close, and then its relative size increases dramatically, is known as the Ames room illusion. This visual effect is achieved through the manipulation of the room's shape and perspective, making objects appear larger or smaller depending on where they are in the room. Our visual perception relies on cues such as size, distance, and the angle of objects to make sense of three-dimensional space.
For instance, when an object is far away, it appears smaller to our eyes. This is because the angle subtended by the object decreases with distance, resulting in a smaller image being formed on the retina. Similarly, when an object is near, the angle subtended is larger, forming a larger image on the retina. This relationship between size, distance, and perceived magnification is a fundamental aspect of visual perception that our brains use to interpret the world around us.
The Ames room illusion plays with these principles, distorting our perception by creating a physical space that does not conform to normal geometrical rules, thereby fooling our visual system into seeing size changes that aren't consistent with natural perspective.