A recent study in the Cleft Palate Journal recorded eye movements of participants that were looking at pictures of faces with and without cleft lip and palate. The participants included patients affected by cleft lip and palate and a control group of unaffected individuals. The results were interesting and showed that the individuals affected by cleft lip and palate focused on the feature of the cleft lip longer than those in the control group.
When looking at faces, our eyes typically follow a top-down pattern known as the scanpath. Our typical scanpath fixes primarily on the eyes, then nose and mouth / teeth. Viewers will fixate initially and for a longer duration on features that draw on their emotions. This is why we think a beautiful smile is so important, it’s one of the first things we see when meeting a new person.