There two types of lens- convex lens and a concave lens. The convex lens is known as a converging lens and a concave lens is termed as a diverging lens. A convex lens is used to focus the light rays to a specific point. And a concave lens is used to spread out the light rays in different directions that fall on it.
A magnifying glass is made up of a convex lens that is used to produce an enlarged image of an object. The first-ever magnifying glass was invented by Franciscan friar and scholar Roger Bacon in the 1250s. It is used to focus light at a single point, such as to concentrate the sun's radiation at a specific spot to create a hot spot at the focus for the fire setting. The lens is usually mounted in a frame with a handle.
A magnifying glass is often used in a detective agency as they need to focus on small objects or to capture fingerprints while investigating any case. Also, they can be used to read small letters and figures. They are also used by scientists to study tiny germs or insects.
The magnification of a magnifying glass depends upon where it is placed between the user's eye and the objects being viewed. Magnifying glasses can make the objects appear larger if the lens is placed close to the object that is to be viewed. In this way, the light rays are bent towards the center of the lens. And when these bent rays reach the eye they make the object appear much larger than it actually is. However, if the object is far enough away from the lens, the image will flip, appearing smaller and upside down. The magnified image is called the virtual image and the smaller, inverted image is called the real image.