They’re just two small arcs, about 250 strands each, and yet eyebrows have become the center of an outsize amount of attention and energy. They’re tweezed, waxed, threaded, shaved, dyed, bleached, micro-bladed, and laminated. They’re penciled, pomaded, powdered, and gelled. They’re skinny, full, flat, and fluffy. And, sometimes, they’re coaxed into proud unibrows.

It’s hard to remember a time before eyebrow groomers, but I do. It was the early 90s, when a few people who specialized in facials or leg waxing suddenly started considering that tiny territory of the face. Before then, I didn’t give them a second thought, or even a first thought. My mother, who never left the house without flawless lipstick and a full manicure, didn’t touch her eyebrows. And then, one day sometime in 1993, we all did. We had brow groomers and standing appointments on the calendar, and that was that. The end of innocence.

In those primitive times, Anastasia Soare was working as a facialist in a Los Angeles salon when she proposed a new service to the owner. “I don’t understand why we don’t do eyebrows here,” she told her. “In Romania, my aesthetician, before I would get a facial, would tweeze my eyebrows.” The owner had no interest, so Soare set up a space in a tiny studio and started building her word of mouth. That included cold-calling publicists to get their actor clients in her chair. She’d tell the publicists, “I could change completely their look with just a few strokes of a pencil.” And it worked! Cindy Crawford, Jennifer Lopez, Naomi Campbell, and Michelle Pfeiffer all succumbed to her tweezers.

Today, Anastasia Beverly Hills, Soare’s brand of eyebrow pencils, pomades, powders, and gels—along with other makeup products—is valued at around $2.5 billion. Note to self: ignore the details on the face at your own peril.

Soare can’t say how many eyebrow products she’s created, so I counted: 117, if you include all the shades; 41 if you don’t.

Skip the grooming, and not only would Soare be flying economy and wearing something other than head-to-toe Chanel, but the rest of us might also be running around impersonating Eugene Levy.

Ask any self-respecting makeup artist and they’ll tell you how crucial the eyebrows are to facial harmony. “They’re extremely important, very,” says Fulvia Farolfi, a makeup artist and ambassador for Chanel U.S. and its @welovecoco Instagram. She sees the current preoccupation with brows as an extension of what she calls “extreme grooming” and “an obsession with perfection. If you’re obsessed with perfection, you’ll eventually find your way to the brows.”

Naomi Biden knows. The granddaughter of the president asked Azi Sacks, the leading brow person of the moment, to come from New York City to the White House to groom her brows plus those of friends and family. “It was nice,” says Sacks, who has a 1,000-person waiting list and is booking appointments well into 2024.

Sacks likes a “fluffy natural look at the front with an elevated arch,” but nothing over-shaped, tight, or angled. She calls it “perfectly imperfect.”

“Imperfect” would not be the word to describe actors’ brows in the past. Joan Crawford’s looked drawn on with a Sharpie guided by a protractor. Marlene Dietrich shaved hers and painted them high on her forehead, perhaps with a compass, looking—strangely—both aloof and clownish. Farolfi said a hairstylist friend witnessed Sophia Loren’s brow methodology in the flesh. “She shaved her brows and then painted them on one by one. She did it on her own, and it would take her a good three hours.” Over the years, brows have traveled from thin and angled to bushy and wild, boomeranging from one extreme to the next and back again.

“If you’re obsessed with perfection, you’ll eventually find your way to the brows.”

There are ever new extremes. About eight years ago, micro-blading entered the picture. This tattooing technique involves permanent dye and fine strokes with a needle to mimic hairs. A friend dove in and looked impeccable for about a month; we were all sick with desire. It liberated her from dyeing and pencils, and she emerged from pools and oceans looking like a high-fashion model.

And then things went completely bonkers. “When people got close, they said I looked like a Kardashian, and that wasn’t my goal,” she said. As summer turned to fall, her brows faded from dark brown to purple, to Groucho Marx. “I had to get the pigment razored out, and it was so painful. Now I just wear sunglasses.”

Soare’s advice to anyone considering micro-blading: see them six months after the treatment. Then she adds, ominously, “they will make their own decision.”

The pendulum swings again, as pendulums tend to do. Bleached brows, a fashion-show perennial, returned to the Paris runways and front rows, making everyone look appropriately blank and alien, as if it were an editorial statement. And just as quickly, the fashion crowd moved on.

Some have headed in the direction of lamination, a three-step treatment that involves a chemical relaxer, a neutralizer, and an oil that makes the brows straight and lacquered. Don’t even talk about it to Sacks. “It looks hard, it looks wet, it looks stiff, and it looks like the brow has been glued to the face. I don’t think that’s beautiful. Maybe with an Instagram filter, it could be attractive, but on a day-to-day woman, it’s just bizarre.”

In the process, they violated one of Farolfi’s rules: Brows should never be the first thing you notice when someone walks into the room. “If they are,” she says, “there’s something wrong.”

Can we leave well enough alone? No, we cannot. We prune and pluck, darken and shape, trying to exert some control over nature. It’s folly, and it’s never-ending. My friend with the formerly Groucho Marx micro-bladed brows just called me and said, “I don’t know—maybe I’ll do it again.”

Linda Wells is the Editor of Air Mail Look