 For years, the tech world has been fantasizing about replacing your phone with a pair of electronic glasses. You might remember the hype around Google Glass back in 2013, but you might also remember that people weren't exactly thrilled by the idea. In fact, they were pretty creeped out, and a lot of people today think of Glass as a failed experiment. But Google didn't actually give up on Glass. In fact, earlier this year, its parent company Alphabet announced a revamped Glass headset and said it was no longer an experiment at all. It's now a full-fledged product. Meanwhile, Facebook and Apple are interested in building augmented reality glasses, and AR startups like Magic Leap are getting huge investments. So why don't you see people wearing them on the street? Well, the reality of AR is a lot more nuanced than the fantasy. To see where these smart glasses live in the real world, we need to look at the big picture. The term AR glasses or AR headsets usually means something that overlays images onto the real world, as opposed to virtual reality, which completely changes what you're seeing. On one end of the spectrum, you've got products like Microsoft HoloLens, which produce detailed 3D objects that look like they're actually sitting in real space. These incorporate tracking cameras and advanced optics tech, but they're often bulky and expensive. On the other, you've got simpler devices like Google Glass, which can look much more like normal glasses, but often just provide a flat visual overlay. And some products split the difference, ending up looking like bulky sunglasses. Tech companies and pop culture spend a lot of time speculating about how AR glasses will change everyday life. You could replace your TV with a virtual screen, for instance, or hang out with a holographic friend in your living room, or see your entire world covered by invasive dystopian advertising. Whether you think these ideas are cool or creepy, they've all got one thing in common. They still haven't happened. So why did Google announce a new glass? And while we're at it, why is the US Army giving Microsoft $480 million for HoloLens headsets? It's 2019, and we keep hearing about AR, but we don't see these glasses on the street. There are some pretty obvious reasons to not wear AR glasses everywhere. A lot of the options are uncomfortable or expensive, and most of them have a limited field of view so they're more like looking through a window than totally changing your view of the world. AR glasses with cameras could enable a kind of nearly invisible surveillance, especially when you add a technology like facial recognition. And things that block your eyes are often just fundamentally alienating to other people. So most AR companies don't think of glasses as the new smartphones. At least not yet. They're content with smaller sales, and they're focusing on specific contexts where there are very clear benefits that outweigh the costs. Microsoft, for example, only sold around 50,000 HoloLens headsets in its first two years, and it's said it's happy with these levels. These days, Alphabet isn't trying to sell glass headsets like Pixel phones or smart speakers. It calls its headsets Enterprise Editions. Instead of the Explorer Edition, it used to pitch as a prototype for consumers. Industrial work is probably commercial AR's biggest market. In fact, the term augmented reality usually gets credited to a scientist at Boeing named Thomas Caudill. In the early 90s, Caudill prototyped a heads-up, see-through, head-mounted display that would let factory employees get information about aircraft overlaid on the actual planes. They could see important points marked on the body or read documentation about things like the plane's incredibly complex wire harnesses. The idea didn't pan out then, but Boeing started experimenting with Google Glass to help with harness wiring a couple of decades later. Boeing announced an official AR glasses test on its factory floor last year. Companies like Vuzix have also been selling AR glasses to these markets. The military is another big AR market. It's been involved in AR for decades. The 80s Air Force Super Cockpit program built fighter pilot heads-up displays into some really bulky helmets. In 2018, Microsoft got that $480 million contract with the US Army, which could get up to 100,000 HoloLens headsets, both for training and for giving soldiers a heads-up display in live combat. Marines had already used the headsets for training simulations. Unlike with consumer AR glasses, these are situations where people are already used to surveillance and bulky, specialized equipment. You don't have to convince a bunch of individual users to each spring for a headset, and the hardware is used for specific tasks where companies can measure their effectiveness. The same goes for other places where AR is used, including surgeons' operating rooms and research institutions. But some companies have been trying to bridge the gap. The National Theatre in London uses Epson Moverio glasses for closed captioning. If you're hard of hearing, you can still see what the actors are saying. Now we're talking about using AR headsets for fun. But it's still limited to a specific place and a specific use that doesn't make other people uncomfortable. Also, it's the theatre, so nobody should be looking at you anyway. When companies try to build all-purpose mass market headsets, things get dicier. Intel and North both designed sleek, relatively cheap glasses for smartwatch-style notifications. But Intel decided there wasn't a big enough market for its product right now. And North also faced layoffs earlier this year, although it's still been rolling out new features. Microsoft used to show off consumer HoloLens apps, but these days it's almost totally focused on professionals. There's one big outlier. AR startup Magic Leap, which has gotten more than $2 billion in funding and focuses on mass market entertainment. We've seen Magic Leap 1 goggles in art installations, and it's hiring developers to make cool apps and games. But we're still waiting to see if Magic Leap has a sustainable business model. Do people want to wear AR glasses all the time? Right now, the answer is still a clear no. But are people wearing them? Absolutely. If you know where to look. Hey, thanks for watching. And if you want to see how a company is designing a new AR headset in 2019, check out our video on Microsoft's HoloLens 2. And remember, like and subscribe.