The plane already was convulsing by the time the "please fasten seatbelt" sign came on. Dark, foreboding clouds filled the sky. We must have been flying right into a storm. All I could think of was that opening scene in Lost where the plane splits in half.

We rode out the turbulence and made an uneventful landing. As the plane came to a stop on the tarmac, I pulled off my goggles, and the virtual world of the cabin disappeared. I was in a conference room in the offices of River, a startup incubator in San Francisco's SoMa district, miles from the airport.

River was launched earlier this year by venture capital Rothenberg Ventures with the goal of advancing the state of virtual reality by providing VR startups with office space plus $100,000 in seed funding. In those offices you'll find hardware hackers working on a new VR headsets and 3D cameras, filmmakers creating lush, interactive digital movies, and developers building the "Ticketmaster for VR events." But most importantly, you'll find VR designers hard at work helping people solve real-world problems today.

And not just "problems" in the sense that too many startups mean as they try to monetize a solution to a minor inconvenience. For years, virtual reality has made inroads in helping to treat serious phobias, post-traumatic stress, and burn victims' pain. Now, as the price of VR tech plummets, this therapeutic tech is advancing—and could soon become available to many more people who need it.

More Than Entertainment

Since Facebook acquired VR company Oculus last year, we've heard a lot about the potential for virtual reality to transform the economy by revitalizing consumer entertainment, social media, shopping, education, and travel. We've speculated about what the killer app for VR might be, or whether it even needs one. Less has been said about the progress VR has already made as a tool for healing. In fields like pain management, physical rehabilitation and the treatment of anxiety disorders such as post traumatic stress, VR is coming into its own. And thanks to the recent emergence of affordable consumer VR rigs like Samsung Gear VR, patients may finally be able to take advantage of technology that's been inaccessible to the larger public for two decades.

Psious

For example, the airline simulation I experienced—created by River company Psious—is a virtual reality version of exposure therapy, an approach to treating anxiety disorders such as phobias and post traumatic stress disorder. The idea is to gradually expose someone to the source of their anxiety—flying, for example—in a safe setting in a way that enables them to face that fear in the real world later. The company offers several other simulators, including ones to help with arachnophobia, fear of needles, claustrophobia, and public speaking.

The simulations aren't perfectly immersive—it's obvious you're in a computer-generated world when wearing a headset—but studies have found VR to be more effective at treating some phobias than traditional exposure methods like mental visualization or photographs. The problem is that historically, VR systems have cost tens of thousands of dollars, making such therapy available to a small percentage of people. Psious, however, is now able to sell a bundle of hardware—including a Homido headset, a smart phone and a haptic feedback device—for $300. "We haven't invented anything," Psious co-founder Dani Roig acknowledges. "We just democratized these kind of treatments."

VR Never Went Away

The conventional wisdom is that VR was vastly overhyped in the 1980s and 90s, and after a few disappointments like Nintendo's Virtual Boy, quietly disappeared until 2012 when Oculus began demoing its Rift headset. But the thing is, virtual reality never really went away.

Just ask Howard Rose, who has spent the past 20 years building virtual worlds for medical researchers. In the mid-1990s, his company Firsthand helped the University of Washington design SpiderWorld, an application for treating arachnophobia. Later the company built Attack of the S. Mutans!, a game designed to help children develop better toothbrushing habits, and IraqWorld, a game designed to help treat PTSD.

But the company's most important project may be SnowWorld, a first-person action game designed to help burn victims manage their pain designed in conjunction with University of Washington researchers led by Hunter Hoffman. Researchers have been using the game to help distract patients from their pain for years. Now Rose and Firsthand co-founder Ari Hollander are now focusing strictly on pain management with their new River-backed startup Deepstream VR.

But while the usefulness of VR for treating acute pain in burn victims is generally well accepted, a review of VR-based pain management studies published in 2012 noted that the research into VR's effectiveness for treating chronic pain is much less mature. The problem, Rose says, is that because VR equipment is so expensive, researchers have focused their time and resources on only the most dire needs for pain relief.

Deepstream VR

That makes this new wave of consumer devices exciting. The earliest practical VR technologies were flight simulators used by the military, and much of the VR hardware industry has focused on this market. "People were making their bread and butter on military gear," Rose says. "And they weren't motivated to make it cheaper."

That's changing. Though much has been written about the Rift's special lens and custom software, Rose says the most important factor driving down the cost of VR gear is the rise of smartphones, which dramatically lowered prices for components such as gyroscopes and accelerometers. "Four years ago we were using $4,000 sensor networks." he says. "Sensors are now really cheap, and they're everywhere. Displays have gotten better and smaller."

Much of this new crop of VR hardware—including the Samsung Gear VR, Google Cardboard, and the VR One—simply place a smartphone into a pair of goggles, displaying a stereoscopic image on the phone's screen and using its internal sensors to track head position.

These gadgets still may be too expensive or not immersive enough to bring about the VR revolution we've been promised for years. But they're fine for therapeutic applications. And by bringing down to just a few hundred dollars, these devices are poised to help doctors, therapists and researchers treat more patients than ever before. About 18 percent of the U.S. population suffers from an anxiety disorder and 7 to 8 percent experience PTSD at some point in their lives. Meanwhile, chronic pain affects 100 million people in the U.S. alone.

Even if VR never becomes a consumer darling, it's poised to improve the lives of millions.

Update 3/5/2015 11:45 AM PST: An earlier version of this story reported that River provides startups $10,000 in seed funding. It's actually $100,000.