It’s not just the implications of virtual reality that can make you dizzy. In fact, it’s a well-known side effect.
Even Oculus CEO Brendan Iribe experienced “simulation sickness” with his own product, the Oculus Rift, while using last year’s “DevKit 1” prototype.
“I’ve gotten sick every time I’ve tried it. Every time until recently,” he said at the Gaming Insiders conference last fall. “In the last few weeks, I stayed in it for 45 minute sessions and I did not get sick with the new prototype. We are at the edge of bringing you no motion sickness content.”
Iribe was talking about the far-from-finished DevKit 2 prototype, which Oculus recently introduced at the Game Developers Conference in San Francisco this month. I looked into why virtual reality makes us sick in the first place, and how the DevKit 2 might deal with the problem.
What Causes Simulation Sickness?
Feeling ill after using the DevKit 1 was so common that there’s a forum for sufferers to discuss it. They call it “Rift Sickness,” and early adopters suggest home remedies from having a beer before using Oculus to testing the product for longer and longer intervals until you finally adjust.
Users of the Oculus DevKit 1 have experienced symptoms including dizziness, nausea, sweating, and vomiting. It sounds a lot like motion sickness, but “simulation sickness,” or “simulator sickness,” is actually the exact opposite.
When you have motion sickness, your body thinks you’re moving, and your brain doesn’t. The inner ear is telling the brain it senses motion, but the eyes are telling the brain that everything’s still. The most common scientific theory behind motion sickness is that the body assumes it is poisoned and hallucinating, and responds by vomiting to void the perceived toxin.
Simulation sickness is similar to motion sickness, except the opposite—your brain thinks you’re moving, while body senses everything is still. The eyes see motion but the inner ear feels nothing. It’s motion sickness in reverse, but the side effects are often exactly the same.
From LCD To Low Persistence OLED
To fix the “simulation sickness” problem, Oculus had to come up with a way to keep your eyes from perceiving erratic motion, even though the movement of one’s head is what causes movement in the Oculus Rift. So far, the solution has been to switch out the hardware of the visual display.
In the original DevKit 1, the Oculus Rift used LCD (Liquid Crystal Display) technology to display visuals. LCD screens can be advantageous since they’re bright, produce zero geometric distortion and consume little electricity. On the other hand, LCD is a particularly bad match for virtual reality for one reason: Motion response time is sluggish. In fact, display motion blur is so synonymous with LCD that it’s sometimes called LCD motion blur.
That’s probably the major reason Oculus moved to low persistence OLED (Organic Light Emitting Diode) display for the DevKit 2. Low persistence OLED may not be as bright or beloved as LCD, but it has a major advantage in delivering crisp, rapid movement without any smearing or ghosting of objects.
Keep in mind that OLED itself doesn’t have this advantage, and some OLED displays (like the one on the PlayStation Vita) can be just as blurry as LCD. However, it’s possible with OLED to significantly shorten the amount of time a frame is displayed by strobing the pixels, which has the same effect as rapid refreshing.
Low persistence OLED simply means an OLED display with a faster frame rate—a rate which presumably can keep up with your movements. But we’ll have to see what developers think of the Oculus DevKit 2 before it can be deemed a true solution to simulator sickness.
Have you tried out the DevKit 2? Let us know if it was smooth sailing, or if you still felt unsteady on your feet.
Photo by Adriana Lee for ReadWrite