When the details are no longer recognizable by the unaided eye, the magnifying glass or the simple microscope is necessary.
A normal eye will therefore see an image formed by the magnifying glass most conveniently when it is produced at a great distance, i.e.
Away; and observation through the magnifying glass must be undertaken by the normal eye with passive accommodation.
This lens is employed in articles found in tourist resorts as a magnifying glass for miniature photographs of the locality.
By introducing a dispersive lens of flint the magnifying glass could be corrected for both chromatic and spherical aberrations.
The first binocular magnifying glass or simple microscope (German, Lupe) was devised by J.