For all its daring, fashion can be tiresomely conventional, its barometer stuck on thinness and youth as baseline traits of beauty. But recently, a force has disrupted fashion’s cult of youth in the form of unlikely style influencers: senior citizens.

Used in high-fashion ads in the late 1990s by designers like Helmut Lang, senior fashionistas had their breakout moment with the 2014 release of  “Advanced Style,” a documentary by Lina Plioplyte about the women chronicled in Ari Seth Cohen's street style blog, which he started in 2010. This year, legendary 71-year-old folksinger Joni Mitchell modeled for Yves Saint Laurent's latest ad campaign, while author Joan Didion, 80, is the face of Celine. Is the fashion world’s infatuation with seniors going to fade away like any other trend, or are we truly witnessing a fashion force that’s here to stay?

In 2010, Cohen began photographing stylish older women for his blog, Advanced Style, which celebrated the senior fashionistas who offer, as he writes in his blog, “proof from the wise and silver-haired set that personal style advances with age.” Cohen started the blog as a way of feeling connected to his grandmother, with whom he was very close as a child, but it was also a way to put the spotlight on women whom fashion generally ignores in its obsessive pursuit of youth.

When asked at a screening of "Advanced Style" Tuesday night at the Jewish Museum in New York City why he focused on senior women for his blog, Cohen said that fashion is harder on women as they age. Unlike men, for whom wrinkles and grey hair can be considered “distinguished,” older women become invisible, cast off. They were anything but invisible for Cohen on the sidewalks of New York City, which he says in the documentary are like runways for the stylish women he would approach and shoot for his blog.

Among its subjects, "Advanced Style" features 93-year-old Ilona Smithkin, who makes her own false eyelashes from her bright-red hair and who says she only truly came into her own in her 80s. Jacquie Tajah Murdoch, an 80-something grandmother, was one of the first dancers at Harlem's Apollo theater and was invited in 2012 to model for a Lanvin fashion campaign. Another documentary subject, Zelda Kaplan, a 95-year-old who had clothes made from beautiful fabrics she bought while traveling in Africa, went out in the most fashionable way possible: She died at age 95 in the front row at New York Fashion Week while the documentary was being made.  

Lanvin Jacquie Tajah Murdoch was 82 when Lanvin invited her to model for their 2012 campaign. She's also a subject of "Advanced Style." Photo: Lanvin

“When one becomes older," Kaplan said, "one has learned to accept oneself. One is not too self-critical.” 

Just as fashion begins to ignore older women, in other words, is when they're becoming comfortable enough to enjoy it and truly hone their own sense of style. This is among the many ironies of “Advanced Style.”

Another irony: that older women are like disruptive outsiders, rather than one of fashion’s core demographic. Having mined street style, biker chic, and hip-hop, fashion is turning to senior women. Call it the Age Quake. "The whole idea of shifting the view onto these women who are older is quite anarchic, provocative and very much against the prevailing fashion system,” says Barneys New York ambassador Simon Doonan in the documentary. "So if you’re looking for a punk-rock anarchy, look at 'Advanced Style.'”

Part of the reason fashion is incorporating senior women into ad campaigns, editorial shoots, and even runways, is of course the industry's desire to attract baby boomers and their considerable spending power. A 2014 Bank of America Merrill Lynch report on the “silver economy,” reports the New York Times, found that average wealth in 50-plus households in the U.S. is $765,000.

Aside from economics, The Beheld beauty blogger Autumn Whitefield-Madrano, thinks our perception of aging is changing. "Julianne Moore still regularly graces magazine covers," Whitefield Madrano told International Business Times, "and she's older than Rue McClanahan was when she was cast in 'The Golden Girls'! And actresses in their 40s are still enormous box-office draws. That's a far cry from women in their 70s, and those actresses don't usually look much older than 35, but it shows that we're beginning to shake up our notions about age and visibility."

Leslie Camhi, a contributing writer at Vogue and author of the forthcoming "The Harem: Yves Saint Laurent and his Women" (Penguin House, 2016), told IBTimes that older women offer a different kind of beauty. "There is a yearning for, dare I say it, depth, or at least the illusion of depth that a face etched with experience can offer," Camhi said. "The trick, in fashion, is to endure. And women like Joni Mitchell and Joan Didion are incredible survivors. And they all still look great. Also, some people age into their beauty. Not everyone looks their best at 20. So there’s always hope!"

Tziphora Tziporah Salamon strikes a pose. Photo: Ari Seth Cohen

Tziporah Salamon, a New York City substitute teacher and favorite of New York Times street style photographer Bill Cunningham, has a simple explanation for why style geniuses like her are becoming the focus of bloggers and the fashion industry.

"I think we're the last of it; we're sustaining standards of style that are quickly being lost," Salamon told IBTimes. "Now it's all about brands, and, 'This is what you should wear.' My work in this lifetime is to raise the bar. To bring back standards. To bring back how women dress, stylishly, looking like women, and not like whores. Beauty heightens energy -- in all its forms. Whether it's a piece of art on the wall, a beautiful sunset, or a baby's feet. Or a beautiful woman. It raises the energy."