Health care depends, in part, on the ability of a practitioner to see signs of disease and to see how to treat it. Visual illusions, therefore, could affect health care. Yet there is very little prospective evidence that illusions can influence treatment. My colleagues and I sought such evidence.

We simulated treatment using dentistry as a model system. We supplied eight, practicing, specialist dentists with at least 21 isolated teeth, randomly sampled from a much larger sample of teeth they were likely to encounter. We found that the dentists made larger cavities in teeth that presented a visual illusion of size, the Delboeuf illusion.

We conclude that the visual context in which treatment takes place can influence the treatment. Undesirable effects of visual illusions could be counteracted by a health practitioner's being aware of them and by using measurement.

Professor O'Shea earned a BSc Honours and a PhD, both in Psychology, from the University of Queensland. Before coming to Southern Cross University in 2009, he held positions at University of Otago, Queen's University, Northwestern University, Dalhousie University, University of Rochester, Harvard University, Dartmouth College, and University of Leipzig.

Professor O'Shea has published 14 editions of various books, 11 book chapters, and 47 papers in high-impact, international, refereed journals. He served as Associate Editor of the international journal Perception & Psychophysics and as editor of the Vision category of Scholarpedia. In 2004, he organized the 31st Australasian Experimental Psychology Conference.

For more see: Professor Robert O'Shea

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