The eye-size illusion is handled by two separate processes

As a visual stimulus, the face is handled by 2 separate processes: the general visual and the face specific. The present study evinces for the first time that the former process is strengthened by the latter when a geometric illusion (handled by the general visual process) is embedded in a face (handled by the face-specific process). This theoretical approach is supported by the following main finding. When a geometric illusion is implanted in a face, the eye-size illusion is generated. Change in or gradual elimination of facial information diminishes the illusion. When all facial information is removed, one obtains a geometric illusion: the rectangle-size illusion, wherein the eyes are replaced by a black rectangle and all other facial features are stripped off. The eye-size illusion is much larger than the rectangle-size illusion. Further results provide additional support for the theoretical approach adopted by the present study.