For low vision patients who need magnification assistance while on the move, there are several different types of devices available, each with their own advantages.
A CCTV (closed circuit television) uses a camera to view an image, which it then projects onto a screen for viewing. While CCTV magnifiers were originally limited to desktop devices because of their size, portable versions are now available, and the versions you can find today are much improved from those original ones. The latest models have larger screens and additional capabilities, such as the ability to adjust for contrast (turning red text black, for example.) Modern CCTV magnifiers also allow the user to adjust the magnification as needed. Desktop versions still exist as well, and tend to be more powerful and able to magnify more text at once, at the cost of being stationary.
Telescope magnifiers are wearable low vision devices. However, many such vision aids are now meant to be used while in motion. The reason for this is the telescopes provide high levels of magnification, so walking while wearing them would be like walking while staring through binoculars–a risky thing to do.
However, some telescopes are not fixed focus and allow the wearer to switch from distance to near vision, granting additional flexibility. Other telescope models have the telescopic lenses mounted high on the glasses, which in turn allows the wearer to look through the carrier lense while moving, and the back through the telescopes upon returning to the task requiring them.
It is important, before purchasing a potentially expensive magnifier, to consult with a low vision specialist and determine just what you need a magnifier for. Additionally, a low vision doctor will be in a better position to recommend quality products to suit your personal needs.