Meniscus lenses are basically a lens with one side as convex and the other side as concave. So it is basically a convex-concave lens. Both the sides of this lens are either convex or concave. This remarkable design of this lens enables it to do what other lens cannot do.

For example the meniscus lenses allow least spherical aberrations when a parallel beam of light enters the surface of lens which is convex. So for the collimated light source the wonderful phenomenon of focus spot size reduction takes place. This is a very useful phenomenon. Meniscus lens also display both positive and negative focal lengths. This means that they also display variety of focal lengths which makes their field of usage a board spectrum one. This specialty of Meniscus lenses have made them very popular. The Meniscus lens experience minimum tensile stress due to their shape.

Types of Meniscus lenses:

There are many types of meniscus lenses. They are as follows:

Positive meniscus Lenses, Negative meniscus Lenses and Aplanatic meniscus lenses

Let us consider them one by one

Positive Meniscus lenses:

These lenses are also termed as convergent meniscus lenses. This is basically a convex-concave lens. This specialty allows this lens to be convergent in nature. Positive meniscus lens is thicker at the center and thin at the edges so there is a marked difference between the central portion and the portion at the edges. The positive meniscus lenses are polished too. These lenses are used unanimously World over in various areas. It is also used in the field of ophthalmic industries. This will illuminate the fact that the accuracy of the positive meniscus lens is tremendous. It is used in situations in which the power of the lens is to be used in diopters. Such is the accuracy of the positive meniscus lens.

Correction of Chromatic aberration with the help of aplanatic meniscus lenses:

Aplanatic meniscus lens is used primarily for the correction of the chromatic aberrations. These aberrations are caused by some lenses as a natural process to happen. Aplanatic meniscus lenses are primarily the meniscus lenses which are designed very properly.

With the use of a Aplanatic lens it is possible to increase the aperture of a doublet with the help of its index of refraction of meniscus lens. So the correction happens mainly by the refractive index of the meniscus lens.

Negative meniscus lenses:

It is a meniscus lens which displays different radii on both the sides. It is used for reducing beam distortion.

This is all about the meniscus lenses.