Each January, the technology industry, or at least a healthy slice of it, gathers in Las Vegas for a glimpse of the future. CES, formerly known as the Consumer Electronics Show, draws more than 180,000 people and 4,000 companies, all of whom are eager to know: Will this be the year [fill-in-the-blank technology] finally makes the leap from science fiction to something people can buy, and might actually want to? 

For the past few years, that speculation has centered on a handful of product categories, including smart home, wearables, virtual reality, and robotics. At this year's edition, which concludes Friday, there was no shortage of dazzling--and not-so-dazzling--demos in these areas. 

Amid the static of startups and consumer-electronics giants clamoring for attention, a few themes emerged as notable.

1. Peace of mind as a product

Are you worried about the quality of the air you're breathing at home, or the water you're drinking? Do you know if your basement is flooding while you're out of town, or if someone jimmied your front door and might be making off this very minute with your brand-new pricey air-quality monitor? Sensor-packed, internet-enabled devices to allay all these fears were in abundance throughout CES. There was even a "smart home cybersecurity hub" that purports to protect from hackers all the devices that are protecting you from everything else. Not worried about any of these things? Give it a few years. Just as Nest and Dropcam convinced consumers it's not weird to have a security camera in your house, once enough of your friends are talking about the particulates in their water, you might feel differently. 

2. AR for work, VR for play

Virtual reality and augmented reality were both on heavy display at CES. It was hard to walk 20 paces through any of the expo areas without encountering someone in wraparound goggles fumbling his or her way through some immersive digital environment. VR prophets say it will soon be a natural venue for all kinds of experiences, from board meetings to live sporting events. But it was hard not to notice the overwhelming majority of VR demos at CES were for video games. Meanwhile, more than a few of the convincing AR technologies on display involved professional applications, like one that used a digital overlay to help guide mechanics through car repairs

3. Robots: Not ready for primetime

It certainly looked like the future had arrived at CES, with robots everywhere one turned. Many, like Softbank's Pepper, took more-or-less humanoid form and were capable of verbal interactions. In theory, anyway. In practice, the most human-like robots often failed to perform, with their creators blaming it on spotty Wi-Fi and the like. (But what's more human than performance anxiety?) For now, the most promising robotic products continue to be the ones that attack narrow problems, like vacuuming floors, and avoid excessively complicated environments.

4. Better sleeping through science

Most people spend between one-quarter and one-third of their time sleeping, a period that's traditionally been a tech-free zone. That's what gadget makers call an opportunity. Among the wares enticing buyers were brain-zapping headsets that purport to induce a deeper state of relaxation, nap pods, smart beds, even a smart pillow (the Zeeq Smart Pillow, $199) that claims to wake you up at the ideal point of your sleep cycle. Never mind that one of the biggest reasons people aren't sleeping well is too much attachment to their devices. 

5. Augmented driving 

Most new luxury cars now come with advanced safety features like lane-following and blind-spot alerts. But most people don't drive new luxury cars. To bridge the gap, a slew of devices, from smart sunglasses to dashboard-mounted head-up displays, offer to help drivers navigate traffic, avoid distractions, and stay alert behind the wheel. Considering the rising tide of casualties from smartphone-preoccupied drivers, this is an idea whose time has arrived.