Research on multimedia learning has shown that learning is hampered when a multimedia message includes extraneous information that is not relevant for the task, because processing the extraneous information uses up scarce attention and working memory resources. However, eye-tracking research suggests that task experience might be a boundary condition for this negative effect of extraneous information on learning, because people seem to learn to ignore task-irrelevant information over time. We therefore hypothesised that extraneous information might no longer hamper learning when it is present over a series of tasks, giving learners the chance to adapt their study strategy. This hypothesis was tested in three experiments. In experiments 1a/1b, participants learned the definitions of new words (from an artificial language) that denoted actions, with matching pictures (same action), mismatching pictures (another action), or without pictures. Mismatching pictures hampered learning compared with matching pictures. Experiment 2 showed that task experience may indeed be a boundary condition to this negative effect on learning: the initial negative effect was no longer present when learners gained experience with the task. This suggests that learners adapted their study strategy, ignoring the mismatching pictures. That hypothesis was tested in experiment 3, using eye tracking. Results showed that attention to the pictures waned with task experience, and that this decrease was stronger for mismatching than for matching pictures. Our findings demonstrate the importance of investigating multimedia effects over time and in relation to study strategies.