[1] Faces appear grotesquely transformed while the viewer focuses on the cross midway between them.
The effect has been applied to Hollywood celebrities,[4] and won 2nd Place in the 8th Annual Best Illusion of the Year Contest[5] held in 2012 under the aegis of the Vision Sciences Society.
The phenomenon, which has gone viral on YouTube, also represents an example of scientific phenomenology which outstrips (in this case) neurological theory.
According to Susanna Martinez-Conde, president of the Neural Correlate Society, which hosts the competition: These are the best illusions of the year, so they’re very new by definition.
We may have theories, but the experiments have not been done, because it’s too early.A 2019 paper in Scientific Reports found that the effect is equally strong when the faces are upside down.