A magnifying glass is used, as the object to be viewed can be brought closer to the eye than the normal near point. This results in (a) a larger angle to be subtended by the object at the eye and hence viewed in greater detail. (b) the formation of a virtual erect image. (c) increase in the field of view. (d) infinite magnification at the near point.
In magnifying glass, the object is placed within the focal length and the image formed is magnified and erect. As (A′B′) image is magnified so it subtends larger angle at the eye than object (AB), so can be seen more clearly
