A concave lens is a lens that diverges a straight light beam from the source to create a reduced, upright virtual picture. It can generate both real concave lens and virtual visuals. Concave lenses feature at least one curved surface inside. A concave lens is also known as a diverging lens because it is shaped round inwards in the centre and bulges outwards through the edges, causing light to diverge. They are used to cure myopia because they make distant objects appear smaller than they are.