Here we focus on cast shadows: the failure to discard these as lighting “artefacts” by misinterpreting them as objects or parts of objects might increase the visual clutter present in a scene. Such a suggestion would fit well with observations that sensitivity to visual clutter increases with age. Visual changes are more marked in patients with Alzheimer’s disease than in normal ageing, and span a wide range of visual and attention-related tasks; for review see. Changes include significantly greater impairments than healthy people of the same age in integrating spatial information to identify form, and in certain types of inhibitory processes. Inhibitory mechanisms are often assumed to be crucial to ignoring lighting-related variability in the visual input, e.g.. Also, we know that other types of brain dysfunction can disrupt shadow processing as stressed above. Moreover, anecdotally, some AD patients experience considerable confusion relating to clutter in the visual environment. We therefore asked whether AD might particularly disrupt the complex processing involved in identifying and correctly classifying “lighting” in the visual input. A methodology which reliably demonstrates categorization of lighting-related visual information was described by Rensink and Cavanagh. Using displays of items interpretable as posts with shadows cast by light-from-above, as in natural lighting, they found slower visual search for a discrepant “shadow” than when searching exactly the same displays inverted, when presumably the items are not seen as shadows because this interpretation is inconsistent with light-from-above. Thus, the visual system has more difficulty in identifying the shape of shadow-like images than of equivalent images which are not interpreted as shadows and are therefore objectrelated; see also. Here we used these same stimuli to test the hypothesis that the separation of “lighting” from “material” might be impaired in Nutlin-3 ageing and especially AD, resulting in lightingrelated information being more visible to these older groups. If so, the differences between searching for shadow-like items and their inverted controls should disappear. The data reported below show some effects specific to ageing and Alzheimer’s disease, but both our older and AD sample groups maintained clear evidence of slowed search among shadow-like stimuli, relative to stimuli which were less shadow-like. This fails to support our hypothesis that older people may find shadows more visible than the young; if anything, the data as a whole suggest the contrary. Thus, despite the complexity of the mechanisms likely to be involved, the “suppression” of cast shadows within visual input appears to survive the effects of ageing and AD. This has implications for assumptions that more complex processes are inevitably more vulnerable to the detrimental effects of ageing. In this study, we looked at a visual task often considered complex and difficult – deciding what is an illumination change and what is a material change. Recent literature has looked at people’s ability to solve such problems, and found that successful solutions depend on integrating several assumptions about light and objects – in particular, that light comes from above and that shadows are dark rather than light, e.g.. Using a paradigm which has been well tested in the recent literature, we investigated the functioning of healthy older people and Alzheimer’s patients on this complex task – and found no deficits in the associated visual processing.