A concave lens is a type of lens that is thinner in the center than at the edges. It diverges light rays that pass through it, causing them to spread out. This property makes concave lenses useful in various applications, such as in eyeglasses for people with nearsightedness, where they help focus distant objects. Concave lenses are also used in devices like flashlights and cameras to control light paths. They can create virtual images that appear upright and smaller than the actual object. This characteristic is essential in optical instruments, enhancing our ability to see and capture images clearly.