Several studies have shown that visual recovery after blindness that occurs early in life is never complete. The current study investigated whether an extremely long period of blindness might also cause a permanent impairment of visual performance, even in a case of adult-onset blindness. We examined KP, a 71-year-old man who underwent a successful sight-restoring operation after 53 years of blindness. A set of psychophysical tests designed to assess KP's face perception, object recognition, and visual space perception abilities were conducted six months and eight months after the surgery. The results demonstrate that regardless of a lengthy period of normal vision and rich pre-accident perceptual experience, KP did not fully integrate this experience, and his visual performance remained greatly compromised. This was particularly evident when the tasks targeted finer levels of perceptual processing. In addition to the decreased robustness of his memory representations, which was hypothesized as the main factor determining visual impairment, other factors that may have affected KP's performance were considered, including compromised visual functions, problems with perceptual organization, deficits in the simultaneous processing of visual information, and reduced cognitive abilities.

Change blindness represents extreme difficulty in detecting changes in the visual field induced by brief blank screen interjected in between two alternating images. In the process of searching for a change, visual saliency certainly plays an important role in attracting attention (i.e., pop-out effect). In our study, we were interested in whether there are high-level scene factors that might attract attention as well. As hypothesized, probable, central, relevant and within the figure changes were detected more easily than changes that were improbable, marginal, irrelevant and occurring within the background. Interestingly, detecting changes occurring within close proximity of the figure was most difficult. This indicates that when searching for changes in scenes, parts of the scenes close to the most powerful attractors are being shadowed, and therefore seem to be ignored by selective attention. This could be ascribed to the role of expectations in change detection task. Therefore, we believe that specifically in explicit change detection task, an individual might use certain heuristics that helps her/him scan the scene. The data are discussed in the context of the debate about the nature of scene representations.