The size of an object appears to decrease as the distance between the object and the observer increases. This is because the angle formed by the lines of sight from the edges of the object to the observer's eyes becomes smaller as the distance increases.

The relationship between the object's actual size (H), the distance to the object (D), and the apparent size (h) of the object is as follows:

h = H / D

As the distance (D) between the object and the observer increases, the apparent size (h) decreases accordingly. The farther the object is from the observer, the smaller it appears.

However, it is important to note that the actual size of the object remains the same regardless of its distance from the observer. It is only the perceived size or apparent size that changes due to the change in perspective and the visual angle subtended by the object at the observer's eye.