Object localization in blurred and jumbled scenes: differences between myopic and emmetropic observers.

PURPOSE To compare the effects of transient blur constraints on the perception of natural scenes in myopic and emmetropic observers. When natural images are blurred, the global structure of the scene-its context-becomes essential for decision making. The authors also aimed to control whether the difference in performance between myopes and emmetropes, if any, resulted from the ability to use contextual information or the ability to process blurred features. METHODS Twenty-four subjects (13 emmetropes, 11 myopes) participated in the study. Subjects were instructed to fixate a target in a scene. Low-pass-filtered images were briefly displayed (100 ms) with normal or jumbled structures. The experiment was repeated three times to assess the ability of subjects to adapt to the imposed blur constraints. RESULTS Results showed that myopes performed better than emmetropes only when scene context was available. Myopes also adapted faster to the jumbling constraint. However, after three repetitions, both groups reached the same level of performance. CONCLUSIONS The present study demonstrated that myopes did not perform better than emmetropes in a transiently blurred environment, but they exhibited better and faster ability to adapt their perceptual strategies to the visual constraints by learning to make use of the relevant information available in the images displayed.