What shape does a concave lens typically have?

A concave lens typically has a shape that curves inward, resembling a dish or a bowl. This inward curvature causes parallel rays of light that enter the lens to diverge, making it behave as a negative lens. As a result, when light passes through a concave lens, it spreads outwards and produces a virtual image that appears smaller than the object itself. This characteristic is essential in applications like eyeglasses for nearsightedness, where the lens helps to focus images properly on the retina. The inward curve is distinct, making it easily identifiable compared to other lens types.