A simple microscope or a magnifying glass is an optical device used to obtain magnification of small objects for better clarity of vision. It is a convex lens of short focal length mounted in a lens holder. To obtain magnification, it is placed at a small distance from the object and virtual image is formed. It is used to see very small letters and figures, by watchmakers, etc.
Magnifying power of simple microscope
m=1+fD D: Least distance of distinct vision (=25 cm) f: Focal length of the lens