Abstract:
The selection of aids for patients with low vision depends upon the optometrist's knowledge of the range of aids available and the properties of these aids. In this paper attention is drawn to certain ‘optometric factors’ as properties of aids. These optometric factors include those of image position and the range over which the image can be moved to allow for the correction of ametropia. For most stand magnifiers image position is not adjustable but is fixed by the relation between focal length and stand height. Methods of coping with this problem are discussed.