Telescopes are used to help distance vision. They may be mounted to
a spectacle prescription so the patient can alternate vision from the
telescope to the carrier (regular portion) of the lens. Telescopes
provide magnification for improved detailed vision, but reduce
peripheral field of vision. They are used as spotting devices and are
not intended for full time continuous vision.
Microscopes are used to help near vision. They provide good
magnification and a relatively large field of view. They are worn like
glasses and do not rely on hand/arm strength or dexterity. They require
a very close working distance to the object of regard, sometimes just a
couple of inches.
Magnifiers are used to help mid-range and near vision. They may be
stand mounted, hand held, or a combination. They come in a variety of
sizes, shapes, and weights. Some are available with lighting built in.
They give less magnification and have a smaller field of view than
microscopes, but have longer (near normal) working distance.
Electro-optical systems are used to help reading. They are stand or
tabletop mounted. Reading material is placed on a slide, which goes
under a scanner that magnifies the image onto a monitor. They provide
excellent magnification, contrast and working distance, but are fixed
(non-mobile) and have a relatively small field of image view.