It's St. Patrick's Day, the day of all things green. If you have green eyes, now is the time to flaunt them.
Emerald peepers have long served as potent symbols in great works of writing, from Othello to Harry Potter. Sometimes they represent beauty, as in the case of Gone With the Wind’s Scarlett O’Hara. Other times, as in Romeo and Juliet, they’re an omen. But almost always, they signify mystery—and even a bit of trickery. In fact, green eyes are not green at all.
Scientists have found that multiple genes, as many as 16, contribute to an individual’s eye color. Essentially, those genes determine two things: the amount of pigmentation in the iris (the colored part of the eye), and the manner in which the tissues of the iris scatter light.
Irises that appear green result from a lower amount of melanin (a pigment that absorbs light and creates color), combined with the scattering of light from the iris, which adds a degree of blue—the same phenomenon that makes the sky and the ocean look blue. A striking example of this effect is the iconic National Geographic cover of Afghani girl Sharbat Gula. At first, it seems certain that Gula’s eyes are purely and distinctly green. A closer look, however, reveals that they actually have a vibrant bright blue exterior, with a center filled in by a light amber-brown.
This isn’t unusual—other colors are often lurking within green eyes. According to the Martin–Schultz scale, a standard eye color scale used in anthropology, there are 16 different eye colors in the world. One is simply green. The other two that involve green are hybrids: gray-green with yellow and brown spots, and green with yellow and brown spots.
But those are just the ways of describing the color that we perceive one’s eyes to be. The only actual pigment found in human eyes is melanin, which is brown; the rest of the color spectrum results from the light-scattering effect.
Like all eye colors, which are partially subjective, it’s hard to quantify the number of people with green gazers. The National Longitudinal Survey of Youth gathered self-reported data from 1985 that sampled eye-color distributions of Americans. Green eyes were found to be extremely rare in black and Hispanic populations. Among 6,000 white Americans, about 30 percent said they had green eyes. In a further breakdown of ancestry, green eyes were most prevalent among the lucky Irish, at about 17 percent.
What’s clearer is that green eyes seem to occur more often in women. The 1985 survey saw slighter more women than men with green eyes. A 2007 study of genetic determinants of eye, hair, and skin color in Icelandic and Dutch adults found a similar result.
Though we don’t know why green eyes may be more prevalent in females, they have certainly been used to symbolize femininity in literature. Perhaps one of the most famous emerald-eyed fictional females is Scarlett O’Hara from Gone With the Wind, whose green eyes—“turbulent, willful, lusty with life”—are symbolically crucial to her character and her femininity.
Margaret Mitchell writes that the Tarleton twins realized that Scarlett had become a woman when they “noticed for the first time how her green eyes danced.” Half-Irish Scarlett, who “liked to believe herself a thing of mystery to men,” is aware of her eyes’ power over the boys, who “were enchanted, as she had intended them to be.” She flirtatiously bats her eyelashes and purposefully wears green when she wants to win someone over: in one scene she feels she looks “attractively saucy” because “the green of the lining made her eyes dark emerald and sparkling.”
Her eyes and character are mirrored in the “wild and untamed” backdrop of the Georgia plantation, where “Bermuda grass and clover on the lawn became emerald, so enticing an emerald that it presented an irresistible temptation.”
Other men have not been shy about their fascination with green-eyed women. In their 2002 song “Green Eyes,” Coldplay sings, “Green eyes, the spotlight, shines upon you. And how could anybody deny you?” The band Filligar wrote a song called “Green-Eyed Queen,” because, as band member Peter Mathias said in an interview, green-eyed women have more “mystery” and are “harder to find, so it’s more of a catch when you do.”
With love and passion comes jealousy, the color’s inescapable cliché. In Shakespeare’s Merchant of Venice, Portia laments her “green-eyed jealousy;” in Othello, Iago warns Othello to beware of envy, the “green-eyed monster.” (Of course, Scarlett O’Hara, Ms. Green Eyes, is as jealous as they come.)
The color has also been used to forebode an omen or a threat. When her nurse is describing Romeo's rival to Juliet, she says, “An eagle, madam, Hath not so green, so quick, so fair an eye.” In Gone With the Wind, Mitchell wrote, “The virgin forests, dark and cool even in the hottest noons, mysterious, a little sinister, the soughing pines seeming to wait with an age-old patience, to threaten with soft sighs: ‘Be careful! Be careful! We had you once. We can take you back again.’”
Scarlett believes her eyes make her mysterious, but in fact they give her away. “The green eyes in the carefully sweet face were turbulent, willful, lusty with life, distinctly at variance with her decorous demeanor.” Ultimately, Rhett Butler’s “black eyes” saw through them, and appropriately symbolically, at the end, the green plantation, once “luscious with promise,” had burnt down to ashes.
Green eyes are caught between two worlds. Pink Floyd, in the song “Green Is the Color,” sang, “Green is the color of her kind, quickness of the eye deceives the mind, envy is the bond between the hopeful and the damned.” They’re wild, but demure; they’re romantic, but jealous; they promise freshness, then signal omen. They’re always playing tricks.
And then, of course, as sure as the sky is blue, there’s the fact that they’re not really green at all.