Illustration by Dan Matutina for The Washington Post

It is a sad truth for technology enthusiasts that it’s almost the end of 2016, and we still don’t have flying cars, a moon colony or fully functional robot butlers. But there is at least one sci-fi technology that is aiming to make a breakthrough into your living room: virtual reality.

Companies big and small are betting that holiday shoppers will get the appeal of being able to pop on a headset and immerse their eyes and ears — and sometimes their hands and feet — in another world. Google, Sony, Samsung, Facebook and HTC are among the major manufacturers that have put virtual reality products, mostly for playing games, on the market in the past several months.

And retailers such as Walmart and Best Buy are building the excitement by setting up demonstration areas in their stores so consumers can get a good feel for these unfamiliar devices.

“For most people . . . this will be their first real opportunity to play with or experience virtual reality,” said Clifton Dawson, chief executive of the market research firm Greenlight VR. “What is really important here is the reaction we’ll see from consumers who walk in these stores and get educated about it for the first time.”

That could make this holiday season a critical period for VR, which is trying to prove it’s not just a gimmick like some gaming trends before it. (Remember the Wii and the Kinect?) Research firm IDC estimates that consumers — particularly gamers — will snap up 9.6 million virtual reality headsets by the end of the year, spending about $2.6 billion.

Gamers, Dawson said, are an obvious key market to watch but so are those looking to use the virtual reality headsets for a family purchase, to replace screen time spent together on the computer to share funny videos or websites, or watching television.

Greg Hall, Walmart’s senior vice president for entertainment, said he expects that gaming will remain tech’s big draw in the near term — but people are “warming up” to virtual reality. “We like the growth,” he said. “We like VR and think it’s got some nice legs for us.”

The full potential of the virtual reality market is still quite a few years away, analysts say. And, in a reversal of the timeline that characterized technologies such as desktops, laptops and cellphones, the appetite for virtual reality is expected to start with average people buying them for their own personal use before the devices break into the business world. Greenlight VR believes the trend will be driven by consumer adoption through 2019, but that applications for business — including education, training and telecommuting — will start to make up the lion’s share of the market after that. The company projects that VR will become a $36 billion industry within the next decade.

A two-tiered market

Given how early in the VR trend we are, there’s a surprising variety of virtual reality headsets on the market.

They come in two main types: Some are self-contained and are used primarily for high-end video games; they allow you to step completely into the virtual world and interact with it. Others work only with your smartphone, and are better suited to passively viewing specially designed 360-degree photos and videos — a super-modern update of the 19th-century stereoscopes that used to show kids slides of the wider world.

If you’re skeptical of virtual reality but are intrigued by more immersive digital experiences, you may want to consider one of the latter type — say the Google Cardboard viewer. It works with smartphones up to six inches high and costs just $15. Other manufacturers are selling cardboard viewers online for even less — some as little as $5.

These are good stocking stuffers for those who want to dip a toe in the virtual reality world, or for families with lots of kids who all want their own viewers. (There’s a reason Google has marketed these heavily to classrooms.) News organizations and other outlets post photos and videos for Google Cardboard on social media, and there are also apps for Android and iOS that work with the viewer to send users on virtual trips around the world, for example, or put them on stage with Paul McCartney in concert.

For a little more polish, you can step up to something like the Google Daydream View or the Samsung Gear VR, which still run off the smartphone but provide a higher-quality experience. The Daydream View, Google’s $79 cloth and plastic headset, also comes with a remote that will let you play and interact with some basic games. And it’s much more comfortable to use — it stays put on your head with a strap, so you don’t have to hold it up.

The Samsung Gear VR is also powered by a smartphone, but it has to be a Galaxy smartphone — specifically, the Galaxy S6 and newer models. With a touch-sensitive control pad on the side of the goggles, the Gear VR is a better choice for light gaming and has a number of high-profile titles including “Minecraft.” At $99, it’s far pricier than a cardboard reader, but it’s a far better experience.

Getting serious

If you’re super-serious and want something that actually lets you interact with the digital world, there are essentially three headset models to choose from: the HTC Vive, the PlayStation VR and the Oculus Rift.

Each has its own strengths and weaknesses. Both the HTC Vive and the Oculus Rift will require connection to a high-end personal computer to work properly — a computer that itself could cost users at least $1,000 to put together if they don’t have a VR-ready computer already.

There are some hidden costs as well. The $799 HTC Vive, for example, does an amazing job of tricking your senses into believing that you’re in a digital world. You really feel as if you can interact with the virtual environment, and several clever software tricks mean that you don’t ever find yourself groping blind for a dropped game controller. One reason it’s so effective is it gives you a lot of in-world space in which to move, and a lot of sensors with which to track those movements.

The downside? You have to give up a lot of real-world space: a suggested minimum of 5 feet by 6.5 feet. You’ll also have to find room to plug in seven pieces of equipment: the computer, monitor, headset, chargers and sensors. That’s fine for a man-cave, but not so much for a studio apartment.

The $599 Rift doesn’t require as much space. In fact, some of its best experiences take place when you’re seated, which means it can be used in a normal office or living room. Its pair of hand controllers, called the Oculus Touch, also let you interact smoothly with the digital world, though they’re not always quite as sensitive — or easy to find when dropped — as those of the Vive.

The Rift shines, however, in the overall quality of its software. As one of the first companies to raise mainstream awareness of virtual reality, Oculus took pains to minimize some of the more unpleasant side effects of moving through a VR world, with rock-solid tracking that should keep all but the most sensitive player from feeling too much motion sickness.

Finally, Sony’s PlayStation VR has the advantage of working automatically with the PlayStation 4 and the newly released PlayStation 4 Pro. That means it doesn’t require an extra computer and runs off the game console that its target audience knows and probably already owns. Among these three high-end headsets, PlayStation VR is also the most comfortable to wear for long periods of time. And it’s just $400 — though you’ve already paid a few hundred for your PlayStation.

If you really want to buy a VR headset but are still having trouble figuring out what works for you, don’t forget to compare each headset’s unique catalog of games first, to narrow down their options.

Or you could take a year or two to think about it. While the hype machine is in full force right now, and consumers are responding, that doesn’t mean that failing to buy a VR headset this year will make you the lamest house on the block. Even VR evangelists don’t see the technology truly becoming mainstream for another couple of years, and that’s if all goes well.

So if you postpone the decision, you may not be on the cutting edge this holiday season; but you may also save yourself some money and space if the analysts’ forecasts are wrong.