He was well acquainted with the use of magnifying glasses and suggested a kind of telescope for viewing the moon, but does not seem to have thought of applying a lens to the camera.
It has mainly to be considered in connexion with powerful magnifying glasses.
In magnifying glasses for direct vision the eye must always be considered.
distant that the two perspectives formed by the naked eye are no more distinguished from each other, recourse may be had to binocular telescopes and range-finders; and if the objects be so small that, in order to observe details on them, we must bring our eyes so close to the objects that they cannot accommodate the images, recourse may be had to binocular microscopes and magnifying glasses.
There are many different types of magnifying glasses and sound augmentation devices available to make it easier for the elderly to enjoy their favorite pastimes.