The effect of handhold magnifier on reading speed
Jiang Li-qi · Yanke · 2010
Objective To study the effect of using handhold magnifier on reading speed in patients with low vision and normal-sighted people. Design Prospective,control study. Participants Low vision (13 patients)and normal-sighted readers (37 persons) who use handhold magnifiers or the first time. Method Nine-point text was read by normal vision subjects without magnifier and then with two magnifiers with different magnification (+10 D,+20 D) in different eye-to-magnifier distance (10 cm,35 cm). Nine-point text was also read by low vision people with magnifiers. The big printed text under the same magnification without magnifier was also read by low vision group. Reading speed was recorded. Main Outcome Measures Reading speed (words per minute). Result For normal vision subjects,reading speed without magnifier (194.6±45.2 words/min) is faster than that with a 10D magnifier in an eye-to-magnifier distance of 10cm (159.7±44.7 words/min) (P=0.001),and distance of 35cm (162.5±46.7words/min) (P=0.002),respectively. Reading speed without magnifier is also faster than that with a 20D magnifier in an eye-to-magnifier distance of 10cm (150.3±43.3 words/min) (P0.001),and distance of 35cm (150.0±43.4 words/min) (P0.001),respectively. For the same magnification,different eye-to-magnifier distance (10cm or 35cm) did not affect reading speed (10D,P=0.783; 20D,P=0.981). For low vision patients who firstly used magnifier,reading speed with magnifier (54.2±8.2 words/min) was slower than that of reading big-printed material under the same magnification (64.0±9.4 words/min ) (P0.0001). Conclusion For persons who newly using magnifier,reading speed was reduced and maximal speed could not be achieved because of the presence of learning effect,including leaning how to coordinate hand and eye and how to locate the first word on the next line.