Reading with low vision: the impact of research on clinical management*

Abstract

The past 40-years has seen a great expansion in low‐vision research, which has changed low‐vision teaching and our clinical management of people with low vision. Australian optometrists have contributed significantly to this research and the development of multidisciplinary low‐vision services. This paper reviews the research that has shaped our clinical assessment and patient management for reading by adults with low vision. The major improvements in clinical assessment of low vision for reading were brought about by the improvements in distance and near visual acuity measurements during the 1970s and research during the 1980s and 1990s showing the factors affecting the reading rate. These changes, together with a different method for representing the magnification provided by optical and electronic systems, allows a scientific, logical and practical method for prescribing magnification. An illustration of the step‐by‐step approach for prescribing magnification for low‐vision reading that is easy to apply in any clinical practice is included.

Key words:

• age‐related macular degeneration
• low vision
• reading
• visual acuity

Abbreviated versions of this paper were presented at both Queensland Vision 2007, the annual conference of Optometrists Association Australia, Queensland and Northern Territory Division (Noel Verney Memorial Lecture) and Vision 2008, the 9th International Conference on Low Vision, Montreal, Canada.

Abbreviated versions of this paper were presented at both Queensland Vision 2007, the annual conference of Optometrists Association Australia, Queensland and Northern Territory Division (Noel Verney Memorial Lecture) and Vision 2008, the 9th International Conference on Low Vision, Montreal, Canada.

Notes

Abbreviated versions of this paper were presented at both Queensland Vision 2007, the annual conference of Optometrists Association Australia, Queensland and Northern Territory Division (Noel Verney Memorial Lecture) and Vision 2008, the 9th International Conference on Low Vision, Montreal, Canada.

a.  The M print size notation refers to the distance in metres, at which the overall size of the lower case letters subtends a visual angle of five minutes of arc.

b.  Point measurement refers to the overall dimension of the type body from the top of the ascending letters to the bottom of the descending letters, with the lower case letters being half the point size; 1 point = 1/72 inch (0.35 mm). Point sizes are commonly preceded by N, for example, N8 (8 point print), which was first used by Law²⁴ simply to indicate ‘near’.

c.  A standard word is six characters.

d.  If the object is held at the focal length of a simple plus lens, only field of view varies with eye–lens distance. The largest field of view is given when the lens is in the spectacle plane.