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Why Can Virtual Reality Make You Dizzy?

If you move in a virtual environment in a way that doesn't match what your body experiences, you'll trigger motion sickness. But unlike seasickness or car sickness VR doesn't require motion, it can make you vomit in your living room.


Everyone has probably experienced motion sickness at some stage.

That sickly, light-headed feeling you get when reading a book in the car or travelling on a boat in choppy seas.

For our brains, it's a product of dealing with mixed messages from what we see and our vestibular system that's monitoring balance in our inner ear.

As neuroscientist Dean Burnett puts it,

"It's getting signals from the muscles and the eyes saying we are still and signals from the balance sensors saying we're in motion. Both of these cannot be correct"

Virtual Reality can cause motion sickness by confusing your senses in the same way a moving car does.

This has been a notorious issue for VR and a personal one for me.

Following the recent launch of Playstation VR, there could soon be millions of people strapping on headsets in their living rooms.

Now is the time to talk about this potential elephant in the room and address the issues that still exist.

For a more in-depth look check out my regular "VR and The Mind" column on VRFocus.

So what's the problem?

If you move in a virtual environment in a way that doesn't match what your body experiences, you'll trigger motion sickness.

But unlike seasickness or car sickness VR doesn't require motion, it can make you vomit in your living room.

And in this sense VR has a lot higher propensity to make us feel ill because all movement is a mismatch to what our body actually experiences.

That is, at least, until we all have full haptic body suits where every physical input and output is reflected in the experience.

Unfortunately, motion isn't the only issue.

Low latency and slow frame refresh rates can create a laggy experience which you might associate with slow loading web pages.

In VR the results are experiences that are disorientating and nausea inducing as well as frustrating.

Optics are another challenge. When in VR we are confronted with the vergence-accommodation problem where our eyes are having to focus on and accommodate a screen whilst also trying to converge on objects in the distance.

And these are just common issues, there are a range of other more specific and complex problems as explored further here and here.

In short, replicating a comfortable virtual reality for our brains is a hard problem.

What is being done about it today?

Reports of the amount of people suffering are mixed.

The general cacophony of VR hype within the industry far outweighs the voices of caution as a VR entrepreneur has recently reflected himself.

Beyond anecdotal individual reports, widespread mass studies simply don't exist yet.

That said, this is something that major players in the industry are paying serious attention to.

Oculus has its own documentation that specifically addresses simulator sickness and provides advice to developers on how to limit the impact.

Developers should avoid taking control of the camera away from the user and limit acceleration wherever possible.

Field of view (FOV) is another area receiving attention.

We see the world in 180 degrees whereas most devices currently provide a FOV around the 100 degree mark.

Logically, for an ever more realistic simulation, we need to drive towards a wider FOV.

Counter intuitively, a larger FOV actually increases the likelihood of motion sickness as we're more sensitive in our peripheral vision.

This is one reason why fixing a user in a static environment such as a cockpit or vehicle can help limit motion sickness.

Microsoft Labs are also developing an innovative solution using LEDs as a replacement for pixels in this wider field of vision.

Yet these methods are more akin to managing the symptoms rather than developing a full solution.

It has developed technology which combines sensors and software to sync up your brain's vestibular system to the virtual experience.

It claims it can use this to reduce the sensory mismatch that causes motion sickness.

It's had limited uptake so far but demonstrates a potentially promising avenue of directly tapping into the fundamental neurological functions controlling balance where all these issues originate.

So what should you do?

Unfortunately, the jury is out on whether motion sickness in VR can ever be fully nullified - if you're susceptible to it, then certain experiences are going to make you uncomfortable.

Ultimately, given our brain's unique propensity to adapt to its environment, the most effective method for people to overcome these sensations is to simply spend more time in VR.

As Oculus themselves state, "experience with VR makes you resistant to simulator sickness (which makes developers inappropriate test subjects)"

Concerningly, in one TechRadar review, despite the reviewer actively noting Black Mirror esque reactions to his VR experiences

"The closest feeling I can pick out is the one where you look at yourself in the mirror and don't really understand the person looking back at you.

You'll still be you, but it won't feel like you at first."

He continues to actively encourage his extended use approach and breezes over the issue -"These side-effects aren't something that concerns me"

Well these side-effects should concern us.

Right now, with so many open questions around what extended exposure to VR could be doing to your brain we need to at least be cognizant of the potential issues.

Simple guidelines are a start and they can be boiled down to three things:

  • If you feel sick at all, just stop, don't wait it out
  • Take regular breaks every 20-30 minutes
  • Talk about it. Rather than dismiss it as one of those things, we need to learn more about what the neurological impact of this technology could be and develop the appropriate guidelines

If VR is ever going to go truly mainstream, more work needs to be done on not just making experiences more comfortable but also understanding the fundamental neurological impact.

Only then can we effectively educate people on how to use this potentially transformative technology.