Meniscus lenses are commonly used in multicomponent optical systems to modify the focal length without introducing significant spherical aberration. The optical performance of multicomponent lens system is usually significantly better than that of single lens. In these systems, aberrations introduced by one element can be corrected by subsequent optical elements. These lenses have a convex and a concave surface, and they can be positive or negative lenses.

Normal meniscus lens:

A meniscus lens is usually used with another lens in a composite optical assembly. When used in this structure, the positive meniscus lens can shorten the focal length and increase the numerical aperture (NA) of the system without introducing significant spherical aberration.

Negative meniscus lens:

Negative meniscus lenses are usually used with another lens in a composite optical assembly. When used in this structure, the negative meniscus lens increases the focal length and decreases the numerical aperture (NA) of the system.