Cybersickness

By Marcello Cherchi, MD PhD

For patients

In simple terms, the word “cybersickness” has been used to refer to “visually-induced motion sickness” (Gallagher and Ferre 2018). Much of the literature on this topic discusses it in the context of VR (virtual reality) environments (such as in video gaming), but in clinical practice, the more commonly encountered situation is that of patients who experience uncomfortable sensations (such as dizziness and nausea) associated with “screen time” (movies or television, working on a computer, etc.).

There is relatively little literature on this topic. Much of the literature about cybersickness extrapolates from previous research on constitutional motion sensitivity (“motion sickness”). There is no widely accepted method for studying cybersickness, and proposals regarding the underlying mechanism of the disease have remained conjectural.

Practically, most patients either practice trigger avoidance, or “break up” the offending visual exposure into smaller, more manageable chunks. We have also seen patients counseled by neuro-optometrists to attempt strategies such as limiting the field of view (in other words, avoid very wide-screen monitors), reduce screen motion where possible, or try a variety of visual filters or lens tints. In patients with very prominent gastrointestinal symptoms, anti-nausea medication may be helpful, though does not eliminate the problem.

For clinicians

Overview

Cybersickness can be provoked when visual stimuli are discrepant with other sensory inputs (vestibular and proprioceptive).  Common triggers include using immersive virtual reality goggles, or simply looking at a scrolling computer screen.  Cybersickness is a relatively recently recognized problem (since the technology producing such visual inputs is relatively recent), and consequently it has not been as thoroughly studied as motion sickness, and there are few data supporting efficacy of any particular treatment.  Practically, most patients practice trigger avoidance; for those who cannot completely avoid the triggering visual stimuli, “breaking up” the exposure into more manageable chunks may be helpful.

Discussion

One proposed definition of cybersickness is, “an unpleasant sensation… [consisting] of symptoms of disorientation, drowsiness, eyestrain, and nausea arising from exposure to immersive VR [virtual reality] environments” (Gallagher and Ferre 2018).

Whereas constitutional motion sensitivity (referred to colloquially as “motion sickness”) is usually induced by actual motion (usually passive motion) of a patient, cybersickness is usually induced by artificial visual stimuli (such as by screens). Although constitutional motion sensitivity and cybersickness tend to occur in different circumstances, the common feature is thought to be sensory discrepancies – which is to say mismatches between the sensory modalities (labyrinthine, visual, proprioceptive) that the brain attempts to process and reconcile through sensory integration (Whiley and Day 2019).

It appears that the longer the exposure to the offending visual stimuli, the more likely it is that an individual will experience cybersickness. The discomfort of cybersickness may persist beyond the visual exposure, and in this respect may parallel the pattern exhibited in motion sickness (where the uncomfortable sensations may persist beyond the actual exposure to motion).

There is not yet any universally agreed-upon framework for studying cybersickness. Research strategies have included assessment of symptoms (subjective, using questionnaires) and measuring physiologic parameters (objective, such as gastric motility, ocular motility or eye blinks, and electroencephalography).

Whereas constitutional motion sensitivity has been recognized for centuries, cybersickness has only been described since the advent of technologies that can induce it, so there is much less literature about cybersickness. There is not yet any widely accepted theory about the mechanisms underlying cybersickness, and most of the literature on this topic extrapolates from that on constitutional motion sensitivity.

Since there is no consensus on how to study cybersickness, and no agreement on the theoretical underpinnings of the diagnosis, it is understandable that there has not been much progress in treatment.

Practically, most patients either practice trigger avoidance, or “break up” the offending visual exposure into smaller, more manageable chunks. We have also seen patients counseled by neuro-optometrists to attempt strategies such as limiting the field of view (in other words, avoid very wide-screen monitors), reduce screen motion where possible, or try a variety of visual filters or lens tints. In patients with very prominent gastrointestinal symptoms, anti-nausea medication may be helpful, though does not eliminate the problem.

References