Results.
During the forward phase, participants primarily used either a straight (47%) or diagonal downward (46%) movement, whereas during the retrace phase, the majority (56%) used a downward movement. On average, forward navigation time was four times longer than retrace navigation time (p < 0.001). The most common navigation error was incorrect positioning of the magnifier at the end of the retrace movement. Near word acuity correlated strongly with forward time (r = 0.78), and moderately with retrace time (r = 0.53) and forward errors (r = 0.50). Vertical field of view correlated with retrace errors (r = −0.53). Participants’ estimates of page navigation difficulties were not predictive of objective measures of performance.
Conclusions.
We quantified page navigation strategies and difficulties of people with AMD reading with magnifiers. Retrace, which presents the most common difficulty, is not well predicted by vision measures or magnifier characteristics; future studies should investigate the relationship between motor skills and navigation performance, and the impact of training or devices on reducing retrace navigation difficulties.