Evaluating if blanking the eyes of individuals effectively ensures anonymity: an ethical dilemma in scientific publications and lectures.

Clinicians and lecturers often use clinical photographs of actual patients for teaching purposes, in congress presentations and for scientific publications. It has been customary practice to blank out the eyes on clinical photographs to ensure anonymity. Researchers have become increasingly concerned that merely covering the eyes is not an effective way to conceal identity especially if the photograph is of a person that may be known to the observer. This study blanked out the eyes of 15 photographs of staff members and well-known public figures as per routine practice in maintaining anonymity. The images were presented to dental students in the final two years of their study, and they were asked to try and identify the individuals. The students were then shown the same images in a different order with no blanked-out eyes and again asked to identify the people. Students were advised that spelling of names was not important. The results were analysed using descriptive statistics to determine the number of correct answers per illustration and in total for both the blanked out and unaltered series of photographs. The results revealed that despite the eyes being blanked out, 75% of the students were able to identify the same number of faces in both series, 21% only had 1 image they could not identify in the blanked out images, and 4% misidentified 2 images. This study confirmed the suspicion that mere blanking out the eyes of an image is ineffectual in ensuring anonymity. It is also evident that most journals are aware of this limitation, and are insisting on confirmation of consent before publishing facial photographs. However, the authors suggest that all lecturers, presenters at study groups and organisers of conferences ensure there is a declaration slide included in the presentation, in which they assure the audience they have gained consent from the respective subjects in their presentations.