What is the primary function of a concave lens?

A concave lens has a primary function of diverging light rays. When parallel rays of light pass through a concave lens, they are spread out or diverged, making the light rays appear to come from a virtual focal point located on the same side of the lens as the incoming light. This is particularly useful in various optical applications, such as in glasses for correcting nearsightedness, where the lens helps to create a clearer image by spreading the light before it reaches the eye.

The properties of concave lenses stem from their shape, which is thinner at the center than at the edges. This design causes incoming light rays to bend outward, rather than converge as they would through a convex lens. Understanding this principle is essential in optics, as it influences how we design systems for vision correction, optical instruments, and other technologies that rely on precise control of light paths.