The phenomenon of light rays from a distant object converging at an observer is due to the way light travels in straight lines and interacts with optical systems, such as the human eye or a camera lens. This process is governed by the principles of geometric optics.
When light rays emanate from a distant object, they spread out in different directions, forming a bundle of rays. However, as these rays travel toward the observer, they encounter a convex lens in the eye or a converging lens in a camera (or other optical devices), which causes the rays to refract or bend.
The convex lens refracts the incoming light rays in such a way that the rays converge toward a focal point after passing through the lens. This focal point is located behind the lens. If the observer's eye or a camera sensor is positioned at this focal point, the light rays will converge at that point, resulting in a clear and focused image of the distant object.
This phenomenon is known as "converging" because the light rays that were initially spreading out are brought together or converged to a single point. The ability of a lens to converge light rays depends on its shape and curvature. The curvature of a convex lens causes it to refract light in a way that brings the rays closer together, creating convergence.
By adjusting the shape or position of the lens, the focal point can be manipulated, allowing for focusing at different distances. This is how our eyes and cameras are able to focus on objects at various distances and form clear images on the retina or camera sensor.