The Mona Lisa, painted by Leonardo da Vinci in the 1500s, is famous for her mysterious smile. We're fascinated by the smile because it disappears when it's looked at directly, says Margaret Livingstone of Harvard University. It's only apparent when we look at other parts of the painting, because of the way the human eye processes visual information.
The eye has two types of vision, foveal and peripheral. Foveal, or direct vision, is picks up detail but is less able to pick up shadows. "The elusive quality of the Mona Lisa's smile can be explained by the fact that her smile is almost entirely in low spatial frequencies, and so is seen best by your peripheral vision," Livingstone says. The more a person stares straight ahead, the less useful their peripheral vision is.
You can test this on yourself by staring at a single letter on a page of print. You'll notice that concentrating on one letter makes it difficult to pick out other letters, even those only a short distance away. The same principle was used by da Vinci?the smile only becomes obvious when you look at Mona Lisa's eyes or focus on some other part of her face. Then you see the smile with your peripheral vision. This makes the smile seem to come and go.
If you want to smile, read about Lilith?the stunningly beautiful vampire who learned to speak English from watching old black and white films on TV.
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