WEDNESDAY, Sept. 15 (HealthDayNews) -- A vision problem just might explain the rich talent of one of history's greatest painters.
According to a new report, the renowned Dutch master Rembrandt was walleyed, a condition that possibly boosted his ability to depict a three-dimensional reality on a two-dimensional canvas.
"Stereo vision," a kind of depth perception, is limited in people whose eyes are poorly aligned. Misaligned eyes are fairly common, and people often don't realize they're lacking full depth perception. In Rembrandt, his apparent walleyes -- which look away from each other -- "would have made him better at seeing" from a painter's point of view, explained Harvard Medical School neurobiologist Margaret Livingstone, who co-authored a study on Rembrandt's vision.
"When you learn how to draw, you have to learn how to flatten the world onto a canvas," Livingstone said. "That's a skill, and it's easier if you have poor stereo vision."
Livingstone, who studies the effects of vision on art, has theorized that a lack of depth perception helps artists get a better handle on the challenge of converting the three-dimensional world into two-dimensional paintings. Unconsciously, artists may know this, Livingstone said: Consider the stereotypical image of a painter with one eye closed -- limiting depth perception -- and a raised thumb.
An estimated 10 percent of people lack "stereo vision," Livingstone said. Some are visibly walleyed or cross-eyed (meaning their eyes look toward each other). "Stereo vision requires your eyes to be lined up, to have the computations happening between the corresponding parts of the two eyes." But people without it can still see depth. Stereo vision "is one of those things that is helpful, but it's not essential."
According to Livingstone, people often don't realize they're affected until they try to look at stereogram Magic Eye picture, which requires eye gymnastics to see a hidden three-dimensional illusion. People with the condition, known medically as strabismus, may also have a hard time viewing images through 3-D ViewMasters or antique Victorian stereo viewers.
Livingstone turned to Rembrandt after noticing that he seemed walleyed in several self-portraits. She said to herself, "Wouldn't it be cool if Rembrandt is stereo-blind?"
Livingstone and a colleague tested her theory by examining 36 Rembrandt self-portraits -- 24 oil paintings and 12 etchings -- to see if his eyes looked the same. They report their findings in the Sept. 16 issue of the New England Journal of Medicine.
In 23 of the 24 self portraits, one eye looks forward, while the other looks to the left side. The situation is reversed in all the etchings, which makes sense, according to Livingstone, because the etching process reverses what is etched on a plate.
Livingstone said several artists appear to have lacked stereo vision, including Winslow Homer, Andrew Wyeth, Pablo Picasso and Man Ray.
The research "opens the doors to understanding that things people think are disabilities turn out to be assets in certain situations," said Livingstone's co-author Bevil Conway, a research fellow at Harvard Medical School.
The findings surprised Tom Rassieur, assistant curator at the Museum of Fine Arts, Boston, because Rembrandt (1606-69) didn't "concern himself to a high degree" with highly accurate depictions of reality. "It's not as thought he cared as much as, say, a Renaissance master about making sure all the proportions were right. He worked with a much more intuitive method," he said. "If I had to choose an artist who was really concerned about the translation from three dimensions to two in a highly accurate way, it wouldn't be Rembrandt."
Regardless of the state of his vision, "there's a tremendous sense of depth of humanity in his art," Rassieur said. "He has an uncanny way of depicting human emotion and human expression, imbuing his figures with a sense of liveliness."
To learn about Rembrandt and his life, try the online encyclopedia wikipedia.com.