Spherical Lenses

SPHERICAL LENSES

A lens is a piece of transparent refracting material bounded by two spherical surfaces or one spherical and another plane surface.

A lens is the most important optical component used in microscopes, telescopes, cameras, projectors, etc.

Basically lenses are of two types :

1. Convex lens or converging lens
2. Concave lens or diverging lens

Convex lens and its type:

A lens that is thick at the center and thin at the edges is called a convex lens. The most common form of a convex lens has both surfaces bulging out to the middle. Some forms of the convex lens are shown in the figure.

Double convex	Plane convex	Concavo convex

Concave lens and its type:

A lens that is thin in the middle and thick at the edges is called a concave lens. The most common form of a concave lens has both surfaces depressed inward in the middle. Some forms of concave lenses are shown in the figure.

Different types of concave lens