At their annual developer’s conference, Apple finally revealed they’re jumping onto the augmented reality (AR) craze. And while they didn’t come out and say it, it’s looking more and more that Apple’s next hardware product will be AR glasses—or at least, some kind of AR wearable device.

What is AR?

AR is any computer-generated image that appears over your view of the real world. To see these manufactured images, you need some kind of screen between your eyes and the world around you, like a smartphone, tablet, or glasses. And these images enhance what you see of your environment using information or entertainment. The wildly popular mobile game, Pokémon Go, which challenged users to catch virtual Pokémon around their neighborhoods is a good example of entertainment. Or think of Snapchat filters that make you look like an animal. And the recent announcement of London’s Gatwick airport providing travelers with an easier way to navigate through the maze of terminals using their phones, is an example of informational AR. Even Google—who has an AR platform called Tango—made a big step forward in AR with their recent announcement of VPS: an indoor, visual positioning service to help you navigate and find what you need in large spaces (like a hardware store). Snapchat is an example of 2D AR—something that’s flat. But 3D AR—which gives a richer sense of depth thanks to things like shadows and perspective—is clearly what Apple’s interested in based on their demo. And doing that takes time and a ton of engineering.

But why would Apple make glasses? And if they don’t have them, why introduce AR now?

Making AR glasses is not easy (just ask Google). While Google certainly didn’t do itself any favors by tossing aside concerns about other people’s privacy, the biggest reason it failed (arguably) was a lack of content or a “killer app”—that one app that’s so good it drives people to buy your product. Getting developers to make quality apps is not a problem for Apple. They have the strongest developer community of any mobile platform. But building complex apps—especially ones they’ve never made before—takes time. So Apple laid the groundwork now to help devs get comfortable with making AR apps by introducing ARKit. And to test those apps, they need something powerful to run them on. And both iPhone and iPad are powerful—and mobile—enough to test those apps. Plus, with iPhone and iPad sales peaking (declining in the case of iPad), here’s a way to sell more devices, help devs get their apps in the hands of users for testing, and get users more excited about AR.

But ultimately, iPhone and iPad aren’t the way users will want to use AR apps.

After the iPad announcement in 2010, then Apple CEO, Steve Jobs, addressed the idea of a touchscreen iMac:

“We’ve done tons of user testing on this, and it turns out it doesn’t work. Touch surfaces don’t want to be vertical. It gives great demo but after a short period of time, you start to fatigue and after an extended period of time, your arm wants to fall off. It doesn’t work, it’s ergonomically terrible.”

While watching the (impressive) AR demo at the event, this quote from Jobs immediately came to mind. iPhone and iPad aren’t heavy devices. But your arms are going to fatigue pretty quickly. So the long-term solution can’t be a device you physically hold. And because the point of AR is not to remove you from your world, but to enhance it to for deeper engagement, that also means it can’t rely on a stationary computer (like VR does). Same goes for a self-contained headset like Google Daydream. So the only other option must be some kind of wearable device.

While the obvious thought leads towards glasses (something rumored since late last year), Apple tends to fork off from convention and come up with something just slightly different. But short of computerized contact lenses (which isn’t new and I could never see them making), I can’t imagine what else they could develop that would allow people to use AR apps without holding a device. And since Apple is all about making devices that lock users deeper into their branded ecosystem, I don’t see them leaving any wearable device to a third-party manufacturer.

Whatever Apple makes, I’m sure will be “magical.” But Apple has first to prove that AR can be successful on their platform. And there’s the looming threat of what could be strong competition from Magic Leap who’ve demoed a similar experience with their product. The next year is shaping up to be fascinating for AR, and for users.

For more on all the announcements from Apple at WWDC—like HomePod, Apple Pay in Messages, iOS 11, and more—check out our other blog posts.