For those people who wish to use magnification to read music, watch TV, see more clearly at the theatre, read notice boards, VDU displays, bus numbers, street signs etc. a telescope of some sort is the only option.
It is very important that anyone who uses spectacle-mounted telescopes do not attempt to walk around when wearing them. This is because telescopes have a very restricted field of view and objects will look much closer than they actually are; a flight of steps 10 or 15 metres away may be seen quite easily but a step right in front of the wearer will not be seen at all.
The exception to this rule is the Beecher Mirage range of spectacle binoculars. These allow the user to see under the telescope so are less claustrophobic to wear.
When sitting down watching TV, or at the theatre, the less expensive - but less powerful - spectacle mounted telescopes can be quite useful because they are very light weight.