In its Wednesday presentation unveiling the new HoloLens 3D headset, Microsoft showed off a number of exotic applications, from exploring the surface of Mars to designing a drone. But one of the most important applications for HoloLens — and other 3D glasses that will inevitably rise up to compete with it — may be something much closer to home: making televisions obsolete.

Instead of watching movies or TV shows on a physical television, families will be able to watch them on a virtual screen floating in the air in front of them.

That might seem silly, but 3D glasses will have some significant advantages over a conventional television. Most obviously, the virtual television projected by 3D glasses will be able to display 3D images. More importantly, virtual televisions can be really big — transforming every living room, no matter how cramped, into a virtual movie theater. Or people might dispense with screens altogether, dropping viewers right into a middle of a virtual movie set or football game. At the same time, because HoloLens is transparent, it won't isolate families who are watching a show together the way older 3D goggles would have done.

Augmented reality means you can still interact with friends and family

Traditional VR headsets completely block out the real world, immersing you in a virtual world instead. This, of course, makes them a poor choice for a family movie night. For most of us, watching movies, TV shows, and sports is a social experience, and it would be a lot less fun if each of us was isolated in our own virtual world.

But HoloLens and its competitor CastAR are a little different. They're "augmented reality" glasses, not "virtual reality" glasses. That means the glasses are transparent, so by default you can still see the real world around you. But virtual objects are projected onto the glasses in a way that makes them look like solid objects that exist in the real world. If an object is sitting on top of a table, it seems to stay in the same position on the table, even as you walk around it.

This makes the technology a lot more appealing for collective video viewing. If everyone is wearing a pair of HoloLens glasses, then everyone can be looking at a virtual screen that looks like it's in the same place and showing the same movie. That means they can laugh at jokes together the same way they would with a normal TV, share a bowl of popcorn, and so forth.

3D TVs haven't taken off yet, but that could still change

An obvious advantage of 3D glasses like HoloLens is that they can automatically show video in 3D. Of course, some recent TVs can do that too, and the feature has totally flopped with consumers.

One big reason for that is that there's relatively little 3D content available right now. Right now, shooting in 3D requires special equipment that's expensive and hard to operate. This creates a chicken-and-egg problem: with little 3D content available, consumers aren't that interested in 3D TVs. And that means it doesn't make sense for content producers to spend a lot of money creating 3D content.

But rapid progress in 3D cameras is likely to change that. Last year, Intel unveiled a new line of 3D cameras aimed at the consumer market. It's only a matter of time before these same technologies become powerful enough for the pros to use. At that point, shooting in 3D will barely be more expensive than shooting conventional 2D video.

Right now, people think of 3D as a gimmick. But as Vox's entertainment writer Todd VanDerWerff pointed out to me, people once considered movies with sound and color to be gimmicks too. That changed as the technology matured and costs came down.

And remember, 3D TVs require you to wear 3D glasses. If you're going to wear glasses anyway, why not just use ones that don't require a TV in the first place?

3D glasses will turn your living room into a virtual movie theater

TVs have gotten bigger over the years, especially as the industry switched from old-fashioned cathode-ray tube TVs to modern flat-screen ones. Still, there are inherent limits to how big TVs can get. Huge TVs — even flat-screen ones — are heavy, they're expensive to manufacture, and they take up a lot of space in your living room.

Virtual TV screens can be as large as you want them to be. They can appear to take over an entire wall in your house, giving you the same wide field of vision you get in a movie theater. They can appear suspended in the air in front of your bookshelves. Even better, they can create the illusion of being farther away than the dimensions of your actual living room. If your couch is 15 feet from the wall, it can look like there's a big hole in the wall leading to a screen 50 feet away.

And eventually, content creators might drop the idea of "screens" altogether. One of Microsoft's demos this week illustrates how this might work. Working with NASA, Microsoft has recreated a 360 degree view of the Martian surface. The NASA employee's desk appeared to be sitting in the middle of the Martian landscape.

Similarly, 3D content of the future could fully surround viewers — it could look like your couch was sitting in the middle of the movie set.

This could be a huge selling point for sports fans. The NFL could mount cameras on a crane or drone over a football field, creating the illusion that a viewer's armchair is hovering over the field. Tennis fans could feel like they're sitting right next to the net, and hockey fans would have the best virtual seats in the arena.

3D glasses will get a lot smaller, lighter, and cheaper

An obvious objection is that people aren't going to want to spend their evenings wearing giant, dorky-looking headsets. But these headsets won't look dorky forever. As the technology matures, the components will get smaller, lighter, and more power-efficient, just as cell phones have. Eventually, 3D glasses won't weigh much more than the normal glasses many of us wear every day.

Microsoft hasn't even announced a release date or price for its new product, but it's likely to be pricey. Microsoft's Kinect Sensor costs $150 to $250; HoloLens headsets combine Kinect-style sensors with several other components, so they're likely to cost even more. The average family of four is unlikely to spend upwards of a thousand dollars just to watch 3D movies.

But like most high-tech gadgets, these devices are likely to get dramatically cheaper over time. Eventually, they'll be cheap enough that most households can afford to own several, just as many households today have a collection of iPods, smartphones, and tablets.