Photographer is my life. / Getty

Recently on Instagram, the former Bachelor contestant Lauren Bushnell had an important message for her 1.1 million followers. Perched on her bed in loungewear, she grasped a new pair of glasses. In the caption, she warned of what might happen to her—and to you—without them: headaches, blurred vision, fatigue, and long-term retinal damage.

The glasses are from Diff Eyewear, a brand that had made only fashion sunglasses until it recently joined a rapidly growing market for glasses whose lenses are intended only to block blue light. Along with other up-and-coming eyewear lines like Quay Australia and Tijn Eyewear, Diff’s new frames are meant to be worn indoors, and they don’t promise vision correction. Instead, they claim to protect your eyes from what these brands say are the damaging effects of your digital life.

In recent months, these brands have tapped an ever larger stable of lifestyle bloggers and former reality-TV stars to get out the word about their glasses (and provide some discount codes as an incentive) through sponsored Instagram posts like Bushnell’s. The only problem is that there’s no science linking blue-light exposure to digital eye strain or retinal damage. For the most part, these glasses are the latest in a long line of fashion products masquerading as health aids in the anxiety economy of social media. For 50 or 60 bucks, which is what most blue-light–blocking glasses cost, you get a pair of frames that looks cute in a selfie and that might help you fall asleep if worn before bed, but not much else.

The claims associated with blue-light glasses are simple enough for an Instagram caption, and the angst they address is common enough to stick with people through the infinite scroll. According to the American Optometric Association, more than half of Americans report experiencing digital eye strain, which manifests in dry, tired eyes, usually at the end of the day. At its worst, it can give people headaches and temporarily blurred vision, which are symptoms that can feel very serious. It’s easy to assume they might be indicative of larger problems or long-term damage, and that maybe you should be safeguarding yourself.

Despite the Instagram fad, “blue light” glasses have been around nearly as long as computers have been a part of regular life. “This first became a thing back in the late ’80s or early ’90s,” says Scott Brodie, an ophthalmologist at New York University Langone Health. The novelty of computers and the unknown repercussions of their daily use initially caused doctors and labor advocates to lobby for increased health protections for workers, Brodie explains—concerns that mirror contemporary fears about the evolving technology of our everyday lives.

Those concerns also turned out to be unfounded. “It was a tempest in a teapot. There was no excess of any eye problem in those patients. It all blew over. As far as I know, nothing of any seriousness has turned up since,” Brodie says. He points out that although these anxieties may feel recent, many people have been using computers all day for decades, and medical professionals would by now be aware of any serious eye damage caused by their use.

The makers of blue-light–blocking glasses tend to skirt around this fact in their marketing by implying a causal relationship between two things that are actually unrelated: the light emitted by digital screens and the strain we feel from looking at any one thing for too long. “Eye strain is about the disparity between the things you want to look at and the natural focusing of your eyes, and how long you do it,” says Adam Gordon, a clinical associate professor at the University of Alabama at Birmingham School of Optometry. A person could just as easily experience the symptoms of digital eye strain from reading a book for eight hours with limited breaks, but many fewer jobs require that, Gordon notes.

This neat obfuscation is made easier by the fact that few consumers know what blue light actually is or where it comes from, except that it’s associated with digital screens. But as Gordon points out, screens are far from the only source. “There are studies that have shown that sunlight, just standing outdoors in the daytime, is like 200 times more intense an exposure to blue light than any screen for eight or 10 hours a day,” he says. If blue light was the cause of eye strain, it would be far worse in those who work outdoors than in office dwellers or heavy smartphone users.

Blue light is just a frequency, and it’s always been an essential part of the human visual experience. In fact, it has health benefits. According to Raj K. Maturi, a professor at the Indiana University School of Medicine and a clinical spokesperson for the American Academy of Ophthalmology, exposure to blue light via the sun helps prevent nearsightedness, especially in kids. Blue frequencies also help regulate humans’ daily wake-sleep cycles by preventing our bodies from producing melatonin during the daytime, which is a hormone that makes people sleepy at night.

Because blue light blocks melatonin production, Maturi did see one potentially smart use for the new crop of fashion glasses proliferating on Instagram: to block blue light in the evening hours, when exposure to it might make it harder for your body to fall asleep. “If you’re looking at your screens late at night, there’s a lot of blue in there, and then your body doesn’t adequately produce melatonin,” he says. Still, Maturi could find no justification for wearing the glasses during the daytime, and the problem of melatonin production can also be addressed via devices’ built-in night modes.

Nevertheless, some consumers swear by their new glasses, even if they don’t do anything to directly affect how their eyes and devices interact. The writer Gina Tomaine wore a pair for a week to document her experience for Good Housekeeping, and although she recommends the glasses, she admits that they functioned mainly as an awareness tool. “Since the glasses made me more aware of blue light, I tried remedying the issue further with small fixes,” she wrote. Those small fixes included avoiding excess screen time and changing the contrast on her devices to be more sleep friendly before bed.

Those changes were what probably made a difference in how Tomaine’s eyes felt, not the glasses—the extra steps she took are what all of the medical professionals I spoke with recommended for consumers whose eyes feel tired, no new products required. Maturi also mentioned a piece of advice that eye doctors commonly give to patients: the 20/20/20 method. To do it, all you have to do is look up from what you’re doing every 20 minutes and switch your focus to something 20 feet away, for 20 seconds. That lets the muscles in and around your eyes relax, and it costs nothing.

If you follow lifestyle bloggers on Instagram, you know that a largely unspoken part of their job is to look like they’ve defeated the vague anxieties of modern life, and many make a living by selling you products and experiences that promise to draw you closer to that ideal. Some of those products, like swan-shaped pool floats or artisanal home textiles, are harmless and fun. Others, like flat-tummy laxative teas and junk-science juice trends, can exploit the difficult and sometimes dark relationship many young people have with their body and the realities of modern American culture. Blue-light blockers provide a quick, fashionable fix to a looming anxiety, and they hit a gap in pop-cultural medical knowledge where people might be inclined to take brands or influencers at their word.

On top of the dubious health claims, there’s the question of whether these glasses even do the most basic form of what they claim: block blue light. The experts I spoke with didn’t know of any professional standards board that would verify those claims, and the glasses aren’t classified as medical devices under the Food and Drug Administration. (Diff Eyewear, Tijn Eyewear, and other manufacturers of blue-light–blocking glasses did not return requests for comment.)

It’s hard not to take a cynical view of these glasses’ sudden popularity among brands that had previously been concerned primarily with fashion. Brodie was similarly skeptical. “People spend so much time on their phones that I’m sure the chance to raise some hell by suggesting a hazard is hard to resist, but there’s no hazard,” he says.

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