Assessment of the Apple iPad as a low-vision reading aid.

PurposeLow-vision clients frequently report having problems with reading. Using magnification, reading performance (as measured by reading speed) can be improved by up to 200%. Current magnification aids can be expensive or bulky; therefore, we explored if the Apple iPad offers comparable performance in improving reading speeds, in comparison with a closed-circuit television (CCTV) video magnifier, or other magnification devices.MethodsWe recruited 100 participants between the ages of 24-97 years, with low vision who were literate and cognitively capable, of whom 57 had age-related macular degeneration. To assess reading, participants read standardized iReST texts and were tested for comprehension. We compared reading speed on the Apple iPad (10 inch) with that of the CCTV, home magnification devices, and baseline measures.ResultsAll assistive devices improved reading rates in comparison to baseline (P<0.001, Hedge's g>1), however, there was no difference in improvement across devices (P>0.05, Hedge's g<0.1). When experience was taken into account, those with iPad experience read, on average, 30 words per minute faster than first time iPad users, whereas CCTV experience did not influence reading speed.ConclusionsIn our sample, the Apple iPad was as effective as currently used technologies for improving reading rates. Moreover, exposure to, and experience with the Apple iPad might increase reading speed with that device. A larger sample size, however, is needed to do subgroup analysis on who would optimally benefit from each type of magnification device.

The Pulfrich effect in optometric practice.

The Pulfrich effect can occur spontaneously, giving severe symptoms of changed visual perception in a variety of conditions in which an interocular latency difference has occurred. The symptoms principally involve misjudgements on the location of objects, especially when driving. Interocular latency differences can inadvertently be created in patients in practice and this study has investigated the Pulfrich effect in anisocoria, uniocular mydriasis, and with uniocular tint (X-chrom lens). In all cases a Pulfrich effect was consistently evident and compared to the size of the effect provoked by neutral density filters. The results show that with anisocoria, uniocular mydriasis and the X-chrom lens, the provoked Pulfrich effect is similar to that found reported previously in cases of trauma. These cases had severe visual symptoms so that care should be exercised in practice, where procedures likely to provoke the Pulfrich effect are contemplated. Specifically, patients who have received uniocular mydriasis in practice should be cautioned about the possible visual effects and advised not to drive until the effect of the mydriatic has finished and equal pupil sizes have been restored.