Two years ago, engineers and executives at Carl Zeiss funneled more than a decade of work on head-mounted displays—and nearly two centuries of work on lenses—into a singular, deceptively simple thought: What if smart glasses looked like glasses? More importantly, What if we’ve figured out how to do just that?

A year later, Zeiss had a single prototype. Now, a year later, it's got a product that actually works. One that can scale, quickly. One that’s just waiting for the right partner, Zeiss executives say, to help realize the full potential of what smart glasses should have been all along.

This isn’t Google Glass. This isn’t Hololens. This is a pair of ordinary glasses—they’ll even work with a prescription—with extraordinary tech hidden nearly invisibly inside. And that may be the smartest thing about them.

Just Glass

There’s plenty to say about wearing Zeiss’s smart glasses, but the most important point—at this stage, maybe the only point—to make is that they feel like glasses. Not clunky glasses, not heavy glasses, not glasses with Coke-bottle lenses or a dorky attachment that telegraphs just how many years in the future you live. They feel like the glasses you wear every day.

That’s hard to accomplish. Very hard. Zeiss did it by integrating a Fresnel structure into a standard lens, and mounting a very small display at the edge of the lens. There are complicated optics at play here, but essentially the light from the display is reflected into the lens and hits the Fresnel structure, which reflects that light into your eye. A smartphone feeds the system images, and a smartwatch controlled navigation in my demo.

Why go through all that trouble, when mounting a system on a pair of glasses like Google did is much easier? For all the reasons you don’t see anyone wearing Google Glass anymore.

“Glasses now are sold by design. It’s an illusion right now to think that somebody goes to an optician and really wants a perfect lens. He just wants a perfect frame that looks good afterward,” says Dr. Kai Jens Ströder, who leads Zeiss Smart Optics, the wholly owned start-up within Zeiss dedicated to making this smart glass dream a reality. “You have to bring the lens to the frame, and adapt the lens that it fits in stylish frames, and not the other way around.”

If nothing else, Zeiss has accomplished this. The glasses I tried featured lenses just 5 grams heavier than standard, a difference the bridge of my nose couldn’t distinguish. The next generation, already in progress, looks sleeker still. This dedication to making smart glasses largely indistinguishable to conventional glasses gives Zeiss a chance of resonating with everyday users. Businesses can, and do, get along just fine with Google Glass or one of a number of similar products. Zeiss’s lenses target an untapped market.

“For business applications, you don’t have to invest so much energy in a small, tiny lens, because it doesn’t really matter if the lens is a little bit bigger and thicker,” says Ströder. "For consumers it does matter. If you really want a product that enables consumers to wear glasses daily the whole time, it must be light, it must look great, it must be small, thin, all this stuff. That’s a completely different challenge.”

Just to be clear, that challenge hasn’t been wholly met. The foundational technology exists, but there’s still plenty of progress left to make before Zeiss’s vision comes fully into focus.

Future Frames

Wearing Zeiss’s smart glasses doesn’t have the same thrill as, say, early Oculus demos did. The actual experience still needs refinement; text is too blurry to read, images are hard to see against a bright background, and the software is rudimentary. The Fresnel structure is positioned slightly down and to the right, and it takes a second or two for your eye to latch on. It’s not as much a heads-up display as a squint-down.

Those caveats, though, belie the true potential of what Zeiss has accomplished. That it works at all feels revelatory. The only awkward attachment was a hookup to a battery pack, something that won’t be necessary if and when an actual production version launches. At least, not all the time.

The display's shortcomings in bright light should be helped, if not entirely remedied, by much brighter OLED displays coming later this year. The positioning and size of the Fresnel structure aren’t locked in; they can go wherever Zeiss’s partners want them to, allowing for a wider field of view (it currently stands at 17 degrees) or more central positioning, if that’s what it turns out customers prefer. As for software, that will come with users, who won’t exist until there’s an actual product, which won't happen until Zeiss ramps up production.

That’s a lot of pieces left to put in place, but at least there are known, achievable solutions to most of the problems. Zeiss has a path forward. And this is Zeiss we're talking about, a company with 170 years' experience in optics, a company that's made countless breakthroughs in everything from eyeglass lenses to electron microscopy. If Zeiss says it can do something, it's earned the benefit of the doubt. And it's not like the company doesn't know the limits of its lenses, and itself.

“Our competence is to provide the consumer the missing link in optics,” says Ströder. “Everything else has to be done by a system integrator who is innovative enough to shape this market. We can only really provide one element, and that’s the optics.”

Until Zeiss finds that partner—last week’s CES was as good a place as any to find one—a lot remains in limbo. Availability and price points are couched in vague words like “soon” and “we’ll meet customer expectations.” The specific demo applications I tried included a map that pointed me to the nearest Starbucks, a video player, and a small handful of others, but real software addressing real use cases will need real developers.

All of this might make Zeiss’s smart glasses sound far-flung, something to round out the decade rather than show up on shelves next year. It’s not. Remember, it took just 12 months to go from single prototype to a working lens that can be produced at a rate of one every three minutes. From here, it’s a matter of fine-tuning. And Zeiss isn’t interested in taking its time.

“One of the key criteria for us in selecting the right partner is who’s really able to get into the window of opportunity that’s now open?” says Ströder. “Time to market is critical. Right now we’ve got a huge competitive advantage with this lens. We really have to utilize it.”

Besides, for any lingering uncertainty over how and when they’ll work, there’s this: You’ll like the way they look. That puts them further ahead in the smart glasses race than anything else—even headline-grabbers like Google Glass, that have already come and gone.