Question

What is a lens? How many types of lenses are there?

Answer 1

A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction. ... Lenses are made from materials such as glass or plastic, and are ground and polished or molded to a desired shape. A lens can focus light to form an image, unlike a prism, which refracts light without focusing.

There are three types of lens.:

1)Convex

2)Concave

3)Bi focal

Answer 2

There are two types of lenses
Convex lens
Concave lens