Low Vision Aids
by Heather Mason
Low vision devices for near and intermediate tasks
| Type | Indications | Features | Limitations |
| Short working distances | Useful for
prolonged reading provided there is adequate magnification for the task. |
Inexpensive, cosmetically acceptable. Provides from 1.5x to 8x magnification. | Short, sometimes very short working distances. |
| Hand magnifiers | For short inspections such as looking at a price tag or an index. As a supplement when necessary for reading smaller print than can be seen with devices used for general reading. | Available in magnifications from 1.5x to lOx. Portable, relatively inexpensive. | Require the use of one hand and no significant hand tremor. |
| Stand magnifiers | Useful for general reading and in the classroom. | Available in magnifications from 1.5x to 15x. Some models may be mounted in spectacle frames. | Best performance only with short working distance, as little as a few centimetres in higher powers. Higher magnifications usually require use of the short working distance. |
| Illuminated hand and stand magnifiers | Useful where performance at near improves with increased illumination. Highest powered optical magnifiers, up to 15x. Useful when away from usual light sources. | Features will be the same as the equivalent hand or stand magnifier. Illumination provided by disposable or rechargable batteries, or by mains operated handles in some models. | Limitations will be the same as the equivalent hand or stand magnifier. Will require a replacement of disposable batteries, changing and recharging of rechargable batteries or mains power. |
| Head-borne magnifiers | For tasks which require use of both hands and where working distance is not critical. | Leave both hands free. Usually mounted on a head band or spectacle frame. | Limited range of magnification. Often cosmetically poor |
| Near point telescopes | For tasks which require the use of both hands and which cannot be done at very short working distances. | Consist of either a distance telescope with a near attatchment or a telescope designed to be used for near tasks only. Mounted in spectacle frame. Longer working distance than other forms or near low vision aids giving the same magnification. | Cosmetically poor. Limited field of view, as magnification and working distance are achieved at expense of field of view. |
| Electronic magnifiers | Where performance with optical magnifiers is not sufficient for needs, because of magnification required or the volume of near work required. | Available in higher powers up to 50x magnification and with better field of view than optical magnifiers. | Expensive. Most models are not portable. |