These feature a similar design to that of standard bifocals, but have a higher addition than normal in the near portion. The distance portion of the lens permits orientation in the surrounding area, while the magnifying portion allows reading and work at close range.
Telescopic spectacles are used to recognize objects outside the range of near vision. With the attachment of a loupe - in the form of a clip-on lens – the telescopic spectacles become "teleloupe" spectacles that are used for activities performed at close range. The benefit of teleloupe glasses over magnifying spectacles is the considerably larger working distance in the near range.
Hand-held telescopes are used for the uncomplicated recognition of details in the distance range and are therefore important aids to outdoor mobility. Models featuring continuous focusing from distance to near offer very flexible application possibilities, e.g. for reading bus or train schedules and street signs or for viewing shop window displays.
Determine magnification required, for example, to read standard font sizes
Demonstrate different optical systems and determine visual outcome