IEEE – Nausea Ratings for Virtual Reality
As virtual reality headsets and VR content become more mainstream, the need for a different type of rating system has emerged—one that ranks motion or nausea risk.
Oculus Rift, a company that has particularly strong name recognition in the VR industry, is operating ahead of the curve by releasing a comfort rating system. Their color and shape-based system helps to classify the content in their store as Comfortable, Moderate or Intense. They want to avoid discomfort when users consume content on Oculus headsets. While the Oculus Rift rating system focuses on comfort, it paves the way for the potential of setting an industry standard in comfort as it extends to motion sensitivity.
From: https://transmitter.ieee.org/nausea-ratings-virtual-reality/
Researchers aren't entirely sure yet why some VR games trigger such physical reactions in their players, but the inherent sensory conflict involved in entering a virtual world — when your eyes and ears are incorrectly informing your brain that you're moving — is key. So, too, is refresh rate, the measure of how many frames per second a headset is capable of displaying. If this drops below 60 per second, it can start to affect the human brain, making us feel dizzy and disoriented. Studies have also pointed to a person's posture, ethnicity, and field dependence or independence— how much of the background they absorb while looking at an object — as changing susceptibility to sickness, but much of this research was conducted before this current wave of headsets arrived on the scene.
From: http://www.theverge.com/2016/3/31/11336430/first-click-does-vr-need-a-nausea-rating-system
Oculus comfort ratings
Comfortable
"Comfortable" experiences are appropriate for most people, although this rating does not confer that an experience is going to be comfortable for everyone. These experiences generally avoid camera movement, player motion, or disorienting content and effects.
Moderate
"Moderate” experiences are appropriate for many but certainly not everyone. These experiences might incorporate some camera movement, player motion, or occasionally disorienting content and effects.
Intense
“Intense” experiences are not appropriate for most people, especially those who are new to VR. These experiences incorporate significant camera movement, player motion, or disorienting content and effects.
From: https://support.oculus.com/help/oculus/918058048293446/