Optical Low Vision Aids

Optical low vision aids use lenses, or a combination of lenses, to magnify the size of objects of regard at distance or near. The lowest magnification compatible with the task to be performed should be used by the patient. The main types of optical devices available are:

Magnifying Spectacles – they have stronger, high-powered lenses compared to the usual eye glasses and are designed for close work. Patients using them need to hold the reading material very close to their eyes in order to keep the print in focus. One needs some practice to get used to these spectacles. They have the advantage of leaving both hands free to hold the reading material. The hands are also freed from holding a magnifying lens, an important consideration in old patients with shaky hands.

Hand Magnifiers – they are the most commonly used low vision devices. They offer greater flexibility because the patient can control their position in relation to the eye or the object of regard. Also, the reading material can be held at the normal distance. Some of them may have a self contained light source incorporated in them.

Stand Magnifiers have the magnifying lens mounted on a stand that rests on the reading material.

Sheet Magnifiers – these are essentially plastic sheets with concentric ridges on their surface. These are available as small size pocket magnifiers or large size book readers. However they provide only low magnification.

Paperweight Magnifiers – they rest directly on the print material, which they magnify.

Bar Magnifiers are useful for reading books or the telephone directory.

Telescopes – telescopes are aids to magnify distance objects. They may be hand held or mounted on spectacles. However they have the disadvantage of reducing the field of vision.