The slow democratization of virtual reality headsets and augmented reality tools raises the question of the impact of these technologies on health. Should we be worried? The scientist Dina Attia, from ANSES, explores the subject for The Conversation.
Virtual reality or augmented reality technologies have become very popular in recent years. Virtual reality headsets, which have become affordable, have found their way into private living rooms, and augmented reality applications or devices have become more common. The first immerse the user in a virtual world generated by a computer, while the second allow him to interact with virtual images that enrich the information coming from the real environment.
These technologies are now used in many sectors, both professional (therapeutic care, training, surgical assistance, help with inventory management, etc.) as well as fun or cultural (video games, immersive room, visit to museums, various cultural experiences, etc.).
As their fields of application are increasing every day, it is important to question the potential harmful effects of their use on health. However, if most manufacturers of virtual reality headsets warn users against possible situations of discomfort (visual fatigue, nausea, dizziness, etc.), and even advise against the use of these devices before the age of 12 or 13 years old, there is no scientific argument on which to back up these usual precautions.
To take stock of the subject, the National Agency for Food, Environmental and Occupational Health Safety (ANSES) has set up a multidisciplinary working group. Here are the main results of the collective expert report that resulted from its assessment.
Three categories of symptoms
As exposure data to virtual reality or augmented reality is scarce, ANSES commissioned a survey in 2019 among a sample of 776 French people aged 18 and over (from a national sample). representative) and 122 children aged 6 to 17 who have already experienced these technologies. Its results tell us in particular that:
- the average duration of a session is greater than one hour;
- among adults, users are more often men (57%) with an average age of 40 years, from higher socio-professional categories (43%) and having a good command of technological tools. The smartphone is the first medium they use;
- in children, a slight predominance of boys is observed (55%), and the average age is 12-13 years. Virtual reality is mainly associated with video games and game consoles are the first media used;
- in the professional context, the two technologies are mobilized, mainly for training, health and inventory management. The computer, virtual reality headsets or screens are the most used media.
Certain effects of virtual reality on health are already well documented, with symptoms whose intensity depends not only on the devices and the content offered, but also on the individual sensitivity of each. They can be divided into three categories.
The first relate to cyber kinetosis (in a way, “virtual motion sickness”, editor’s note). The second are the result of sensory incongruences, in other words of a bad adaptation of the sensory signals perceived between them (the eyes perceive something that the body does not feel, when it should, for example, editor’s note). Finally, in the third category of symptoms are those related to the light emitted by the screens.
What is cyber kinetosis?
During a virtual reality session, some people may experience very uncomfortable symptoms, grouped under the name of cyber kinetosis: pallor, feeling of being unwell, visual disturbances, disorientation, headaches, fatigue, dizziness, nausea, vomiting, tachycardia , hypersalivation.
According to the survey commissioned by ANSES, cyber kinetosis affects between 30 and 50% of users. The figure varies depending on the interaction medium in the virtual world, the age of the users, and the population considered (age, gender). These symptoms can appear quickly (within five minutes of the start of the experience), but usually go away quite quickly after the session.
Their occurrence depends a lot on the content. Roller coaster-type rides will obviously be more likely to result in kinetosis than a calm and calming experience. But the requested visual field also plays a role (the larger it is, the stronger the symptoms can be), as well as the visual interface and the mode of interaction.
Effects persisting for several hours after the VR session
During an immersion in a virtual universe, our organism seeks to adapt to the world in which it is immersed. For this, the brain makes a considerable cognitive effort. However, the expert appraisal work carried out by ANSES revealed the existence of harmful effects following at a session, in connection with the sensory incongruences generated by virtual reality.
These effects are manifested by difficulty in regaining optimal manual skills and orienting yourself in the real world. They can persist for several hours after the virtual reality session. It is assumed that the return to previous performance depends on the type of sensory incongruence that has been experienced.
Screen light can disrupt the circadian cycle
This affects the internal clock and circadian rhythms. In addition, the temporal modulation of light (variation over time in the light intensity of screens) can cause headaches and visual fatigue.
Users of virtual reality devices are exposed to radiation from screens, especially the blue light they emit. The source of radiation during this exposure is very close to the eyes, and two questions arise: the effects of the amount of blue light received by the retina and its spectral composition, as well as the time of day when this exposure takes place. ‘somewhere else.
Remember that in its 2019 expert report on effects on human health and the environment of light-emitting diodes, ANSES concluded that the effect of rich blue light on short-term retinal toxicity is proven, as is its contribution to the occurrence of AMD (age-related macular degeneration) and its consequences. disruptive effects on the body clock (circadian rhythms). The phototoxicity of blue light depends on the quantity of blue light received by the retina (luminance) but also on the time of day when the exposure occurs.
In the case of virtual reality devices, the luminance of the screens is low. However, it is questionable about the effects of long-term exposure at a short distance from the eyes. Above all, any exposure before bedtime can interfere with the regulation of circadian rhythms and disrupt sleep in the event of late exposure, before bedtime, even at low intensity. The problem particularly concerns children and adolescents, whose maturing crystalline lens filters blue light very poorly.
Finally, a measurement campaign on virtual reality headsets was carried out on the occasion of the ANSES expertise. It demonstrated a high rate of temporal modulation of the light emitted – that is to say fluctuations in luminance – in a frequency range going from 70 to 90 Hz. However, this phenomenon is likely to generate headaches. , migraine, visual fatigue, even triggering seizures in people with epilepsy in the frequency band from 1 to 80 Hz, and this even if our eyes do not necessarily perceive it.
The four recommendations of ANSES
In fine, with the aim of prevention, ANSES recommends that users:
- to quit any virtual or augmented reality session as soon as symptoms appear such as nausea, dizziness, sweating, pallor;
- observe a rest period of one to two hours after using these devices to take into account the effects induced by the sensory incongruence of virtual reality;
- avoid screens two hours before bedtime, especially for children and adolescents, who are more sensitive to blue light from screens.
- also avoid these devices in cases of epilepsy or in patients with populations identified as sensitive to exposure to these devices : pregnant women, people suffering from motion sickness, having balance disorders, or prone to migraines, etc. An exhaustive list of these susceptible populations can be found in the [ rapport d’expertise collective de l’Anses].
Scientific data that would allow quantifying a certain number of disorders potentially induced by the use of virtual reality devices are still largely lacking.
Not only do we lack studies on the psychosocial, psychological or neurological effects of these technologies, but we also know too little about the possible musculoskeletal disorders resulting from their use, on the risk of accidents linked to the ergonomics of the devices. (encountering an obstacle in the real world during a virtual immersion for example), or on the impact of the use of an avatar. Understanding the very real effects of virtual reality will therefore take some time yet …
Dina Attia, Scientist, senior project manager, National Agency for Food, Environmental and Occupational Health Safety (ANSES)
Source: Numerama by www.numerama.com.
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