The Influence of Manual Dexterity on Reading Speed with a Hand-held Magnifier

Abstract

To determine whether reading speed with a hand-held magnifier is influenced by age-related manual dexterity decline. Two groups of normally sighted individuals who were inexperienced in the use of a magnifier were recruited. The older group comprised 15 subjects 60 to 85 years of age, and the younger group consisted of 12 subjects 18 to 30 years of age. Subjects' reading speeds were measured under three conditions: (1) reading 12-point print without a magnifier, (2) reading 3-point print by moving a hand-held magnifier across the page, and (3) using the same print and magnifier, but moving the text under the stationary magnifier. Manual dexterity was assessed using the Jebsen-Taylor hand-function test, upper arm motor coordination with the finger-nose test, and grip strength using the Jamar dynamometer. No significant difference was found between the two age groups in the mean reading speed for unmagnified text. Reading speed with a magnifier was significantly reduced in the older group, but not in the younger group. In both groups, no significant difference was found between moving the magnifier and moving the text during magnifier reading. Grip strength did not differ between the groups. The Jebsen-Taylor and finger-nose tests, however, showed poorer manual dexterity in the older group, and these correlated with the reading speed with the magnifier. Manual dexterity should be considered as a possible prognostic factor for successful use of a hand-held low-vision aid. It is not known whether the deficit can be overcome with suitable training.