Differences Between Protocol And Review: 2013 update: •We decided to remove the RCT filter from the electronic searches in order to identify as many potentially relevant studies as possible. We also specified that reading speed had to be measured at ordinary print size because this is the outcome most relevant to patients in terms of performance using a specific low-vision aid. We also specified that MNREAD definitions of maximum reading speed and reading acuity were adopted in our review and the consequences of this choice are discussed in the revised version. •We used raw reading acuity (words per minute) rather than its log transformation, as done in the original version using individual values, because results are more interpretable on this scale, despite mild skewness. •We also adapted the 'Risk of bias' assessment following new guidance. We reconsidered the scoring of 'within-subject' or crossover-like studies, leading to adapted criteria to score the quality of randomisation and allocation concealment.