Meniscus lenses have two curved surfaces, one with an outward-curved face and the other with an inward-curved one. These lenses are also referred to as convex-concave lenses. The radii of the curvature of both surfaces can be chosen independently of each other.

Meniscus lenses are used in optical systems, in which aberrations need to be minimized. They are, for instance, used in multi-lens focusing objective, where they help to minimize the beam’s focal spot. The same benefit is applied in collimators.

Lenses with equal curvature radii on opposite sides are often used as substrates for output couplers or variable reflectivity resonator mirrors.