VR sickness is no secret. Although headset-makers would probably prefer that it was one.
In searching the documentation for the four main headsets(HTC's Vive, Oculus' Rift, Samsung's GearVR, Google's Daydream), only Oculus has guidelines for developers designing VR content to minimize nausea and discomfort. I haven't read the manual for all of the headsets but neither the Vive's nor the Rift's say anything about VR sickness or nausea in their user guides.
And this shouldn't be. Oculus, HTC, other headset-makers — you guys need to get on this. Face the problem head on, rather than giving devs some basic guidelines to follow, and not mentioning a word to your users. You need to make your users aware of the "simulation sickness" that inevitably occurs when using a VR headset, and give them some best practices for how to deal with it when VR sickness happens.
Be that as it may, I wrote this post as a resource on VR sickness, for users and developers.
The Good News
The good news is that this is an issue that lots of people are thinking about, writing about, and doing research on to find solutions. I can assure you that researchers, game designers, VR hardware companies, and software designers care very, very much about solving this problem. Because VR sickness is bad for business.
On the first use of the Vive, I was left feeling slightly-nauseous, and noticeably disoriented. I had trouble holding a conversation with my always-amiable roommates and went to bed early. This was from merely playing around in Tilt Brush for 15 minutes.
I have noticed that I seem to be building up a tolerance to it. Raw Data definitely would've made me pretty sick if that had been my first VR experience. However, I hacked and slashed killer robots for around 45 minutes last night and seemed to be fine afterwards.
Which is a good sign. Like a broken record, I keep repeating the phrase, "I really want to like VR". I'm not sure I'm ready to give it a 100% thumbs-up, but first thing is first — virtual reality needs to solve it's nausea problem.
...the eye-brain combination may be able to adapt, as it has for many aspects of displays. But such adaption may not be complete, especially below the conscious level, and that sort of partial adaption that may cause fatigue and motion sickness. And even when adaptation is complete, the process of adaptation can be unpleasant, as for example is often the case when people get new eyeglasses. It’s going to take a lot of R&D before all this is sorted out, which is one reason I say that VR is going to continue improving for decades.
I love that last bit: VR is going to continue improving for decades.
So, what exactly are VR's effects on human physiology?
Virtual Reality and The Human Body
As a youth, I played video games for up to 8 hours at a time. When I first got a Playstation(the first one — I'm 31, which makes a person "old" these days), I would rent Final Fantasy VII from the local video store on Friday evening and, since I didn't have a memory card to save the game, I would literally play it for two days straight before reluctantly plucking the disc from my PS1 and going with my parents to return it Sunday night. And then I'd rent it again the next weekend to see if I could get further in the game. I did this at least three times.
This kind of all-day gameplay is not possible with VR. Yes, in the above example I was young and relatively fit("relatively fit" is a relative term — ha), but VR is obviously a whole different experience than gaming on a flat screen. Research has shown that those who are young and in good physical shape are less susceptible to VR sickness, but I'll get to that later in the post.
Scientists have known about "simulation sickness"(VR sickness is a kind of sim-sickness) since the 1950's, when the first flight simulators were used to train Navy pilots. It's actually a fairly challenging technical problem to solve(see Michael Abrash's quote above).
How Are VR Headsets Built and Why Do They Make You Sick?
A VR headset is basically a high-intensity video monitor mounted on your face, with two lenses that give your brain the illusion that the two side-by-side images you're seeing on the headset's screen are actually a 3D environment, populated with 3D things.
The human body does not like this. Why?
Well, Wikipedia states that “The physiology behind VR sickness is not currently clearly understood”, but the general theory behind simulation sickness(and VR sickness — using them interchangeably since VR sick is a kind of motion sick) is that happens because of a mismatch of sensory information. Your eyes and ears are taking in information that you are running around on a spaceship blasting evil robots. Your vestibular system(which gives you your sense of balance) relays conflicting information: you are sitting or standing in a more or less stationary fashion, and you are, in fact and in real life, not running around blasting robots.
VR Safety for Users
Lifehacker wrote a decent article about what users can do to minimize nausea in VR. I'll give you the bullet points:
- Being seated is best.
- When you have the headset on, move your head as slowly, as little as possible.
- Reset your headset if it's glitching.
- Don't eat heavy foods.
- Cold air helps. Sometimes the body responds to being in VR by getting hot/having hot flashes.
- Sometimes acupressure works. Seriously. Some people use Sea Bands, which you can wear on your wrists to minimize nausea.
- Ginger tea or chewing gum can help.
- Oddly enough, drinking a small amount of alcohol works for some people. Caveat emptor.
Also, taking a 15-minute break for every hour of gameplay is recommended.
Best Practices for VR Designers and Developers
A good place to start is Oculus' documentation for designing to minimize "simulator sickness". If you're at all interested in making VR content, it's worth a read.
Once you've read that, Ryan Betts' Medium post, Practical VR: A Design Cheat Sheet, is a killer resource on UX/UI in designing for VR. And how.
Jean-Marc Denis, a designer at Google, wrote a more exhaustive, less-accessible(but still worthwhile!) post about designing for VR, mostly about the fundamentals and how to prototype for VR.
Virtual Reality Research
Besides available guides and documentation, there's actually a great deal of speculation and research when it comes to solving VR sickness.
A recent Popular Science post mentions research that suggests putting a fake nose in the viewer's field of view helps alleviate nausea. Another study advocates lessening the user's field of view in relation to the amount of motion they are experiencing at any given moment, and then slowly widening the field of view again as the user becomes more stationary. If that sounds complicated, it's not but might better explained via the above hyperlink.
More Fun Facts About VR Sickness
- It appears that people with "type-A" personalities tend to get sick in VR more easily. The hypothesis is that type-A people are more acutely sensitive to changes in their environment.
- Suffice to say that VR is not motion sickness, but seems to be directly-related in it's effects and etiology. A Cambridge study on motion sickness found that the highest incidence of susceptibility was recorded among schizophrenics, and the lowest incidence of susceptibility was found among rowers(go figure). One might speculate two things from this: 1) some people's brains are not going to work with VR, 2) nausea may be alleviated through exercise that conditions postural alignment and balance.
- VR sickness actually gets worse as the authenticity of the simulation increases. For some reason our brains have a harder time with higher resolution, more realistic VR experiences, rather than cruder, more abstracted ones.
- Seniors and children are especially vulnerable to VR sickness. One study states that the most robust age group for VR is 22, plus or minus 6 years. KQED's Mind/Shift blog has an excellent post on ethical considerations for using VR with children and adolescents. Highly recommended for educators, parents, and VR creators.
The long-term effects of VR on human physiology are unknown. VR does affect proprioception and hand-eye coordination after coming out of VR. Scientists are researching "readapation strategies" to off-set these symptoms.
How We Address VR Sickness in the Industry, For Starters
As stated above, I firmly believe that headset-makers need to do a better job preparing users to deal with simulation sickness. It's Facebook/Oculus, Google, HTC, and the like leading the charge on VR best practices. These corporations need to be more responsible and address user safety in VR more directly. If done in the right way, I think that more users would adopt. I think many are reluctant to purchase a headset because it is common knowledge that VR can and, at least in the beginning, will make you sick.
The Khronos Group is working with leading VR hardware designers and platforms to create VR standards for cross-compatibility and portability for VR content — I would like to see them add user health standards for VR experiences to their mission statement.
Furthermore, doctors need to be educated on the effects of VR on human physiology.
There's a website called, moviehurl.com, which rates how likely a particular movie is to make you vomit. VR experiences need a rating system like this, and maybe independent and informal is better. Resident Evil VR and Drive Club VR would seem to receive high "hurl ratings" on a site like this.
Research finds that VR headsets may be sexist in their effects, as the male physiology handles VR sickness than the female. This could be a big problem for VR in a cultural climate in which gender biases are finally starting to be addressed after hundreds, possibly thousands of years.
Lastly, no one really knows what the long-term after effects of VR use are. In these runaway, fake-news, troll-ridden times, common sense seems to have become a thing of the past, at least with regards to global media. Corporations use PR to hide possible design defects in the newest, hottest tech and it's the users that are the ones burdened with the labor of finding out the physical costs of using these devices.
I'm not going to stop using VR, but going forward I'm definitely going to be careful in how I use it, and in how much I use it. I implore you, kindest of readers, to do the same.