What Is Simulator Sickness and How Can You Prevent It?

Simulator sickness is a form of motion sickness caused by virtual or simulated environments, such as virtual reality (VR) headsets or flight simulators. It is not caused by physical motion, but by the visual perception of movement. What was first identified in pilots using flight simulators is now a more widespread issue as immersive technologies become common.

The Sensory Conflict

The cause of simulator sickness is a sensory conflict. Your eyes perceive movement within the virtual environment, sending signals to your brain that you are in motion, such as soaring through the sky or racing in a car.

Simultaneously, your vestibular system in the inner ear, which manages balance, reports that you are stationary. Since your body is not physically moving, it tells your brain you are still. This creates a contradiction between what you see and what you feel.

The brain struggles to reconcile these opposing signals. One hypothesis suggests it interprets this clash as a sign of being poisoned and initiates a defense mechanism. This neural confusion is the trigger for the symptoms users experience.

Common Symptoms

The most common symptoms relate to nausea and general physical discomfort. These feelings can range from mild stomach awareness to intense nausea, sometimes accompanied by sweating and a feeling of warmth.

Disorientation and balance disruption are also common. Users may experience dizziness, a spinning sensation known as vertigo, and general unsteadiness. These feelings can persist even after the simulation has ended, making it difficult to reorient to the real world.

Oculomotor problems are also frequent, stemming from how the eyes track and focus in a virtual space. Symptoms include eye strain, fatigue, headaches, and difficulty focusing. Looking at a fixed-depth screen so close to the eyes, while the brain perceives depth, puts a strain on the eye muscles.

Factors That Worsen Symptoms

Several technical and personal factors can increase the severity of simulator sickness.

• Latency and Frame Rate: High latency, the delay between your movement and the screen’s update, is a major factor, as are low frame rates that make the world appear choppy.
• Experience Design: Simulations with rapid acceleration, quick rotations, or an unnatural field of view are challenging, especially when the user cannot control the camera.
• Duration of Exposure: Longer sessions in a virtual environment increase the likelihood of symptoms developing.
• Individual Susceptibility: People who are prone to motion sickness are often more sensitive, and while experience can help, adaptation is not guaranteed.

Managing and Reducing Discomfort

To manage and prevent simulator sickness, gradually acclimate your body to the virtual environment. Start with short sessions of 5-10 minutes and slowly increase the duration as you become comfortable. Taking frequent breaks is also beneficial to allow your senses to recalibrate.

Ensure your VR hardware is properly calibrated and fits well. The interpupillary distance (IPD) should be set correctly on the headset to align the lenses with your eyes, which reduces strain. A secure fit prevents the headset from shifting and helps maintain a stable visual experience.

If you begin to feel symptoms, stop immediately, as pushing through the discomfort will only make it worse. Closing your eyes for a moment can help reset your sensory system. Focusing on a stable object in your physical room or getting fresh air can also alleviate nausea and disorientation.