Table 2.

Overview of the physical domain

	References	Publication Type	Cybersickness	Obesity	Radiation	Sleep disorders	Visual symptoms	Study summary and Authors’ conclusions
1	Calvert et al. (2013)	Research article		*				Exposure to electronic game play is often implicated in the obesity crisis because may promote sedentary behaviour and increase consumption of high-calorie foods with low nutritional value. However, games may increase children’s physical activity and expose them to healthier foods
2	Dużmańska et al. (2018)	Review article	*					VRTs still tend to evoke unpleasant symptoms among their users; although technology advances, this problem has not yet been solved. In most cases, the severity of symptoms increases with time of exposure and a threshold level or time point exists, after which the symptoms stop increasing or begin to decrease. Symptoms may persist for a short period (10 min) or a relatively long one (even 4 h)
3	Fernández et al. (2018)	Research article			*			Modelling of a cell phone held to the ear, or VR devices in front of the eyes reveal that young eyes and brains absorb substantially higher local radiation doses than adults. Age-specific simulations indicate the need to apply refined testing methods and for public education regarding manufacturers' advice to keep phones off the body, and prudent use to limit exposures, particularly to protect the young
4	Fuller et al. (2017)	Research article		*		*		Using any device at bedtime was associated with a statically significant increased use of multiple forms of technology at bedtime and use in the middle of the night, reducing sleep quantity and quality and elevating body mass index
5	Gheller et al. (2019)	Research article		*				Video game playing (VGP) is associated with overweight/obesity (OW/OB). VGP and caloric preloads in the pre-meal environment influence short-term food intake (FI) in healthy-weight children. Authors' findings indicated that, unlike boys with healthy weight, boys with OW/OB do not reduce their FI following 30 min of pre-meal VGP and exhibit impaired caloric compensation after a glucose preload
6	González et al. (2016)	Research article		*				Increasing childhood obesity in the world is a direct result of changes in the lifestyles of the population. Active video games have a positive effect on the prevention of obesity. The results involving biometric variables, learning healthy habits and experience in the intervention were highly satisfactory
7	Gottschalk (2019)	Review article		*	*	*		It has been suggested that moderate use of screens is not associated with problematic outcomes such as delinquency, risky behaviours, reduced grades or mental health problems. If screen time is displacing other activities such as physical activity, interacting with family and peers, or adequate sleep time, this would be cause for concerns including radiation effects, sleep patterns, posture and sedentary behaviours
8	Greuter et al. (2020)	Research article					*	Few studies have considered the binocular affordances provided by VR headsets and the engaging qualities of electronic games as a treatment. AmblyopiaVR is a system that calibrates a user's VR view separately for each eye and engages them in play experiences. This paper presents the conceptualization and design of the system and its implementation, prototype-game ideas, and future user testing plans
9	Hirota et al. (2019)	Research article					*	Objective and subjective evaluation of visual fatigue were not significantly different with the use of a VR-HMD and two-dimensional display. These results should be valuable not only to engineers developing VR content but also to researchers involved in the evaluation of visual fatigue using VR-HMD
10	Kardefelt-Winther (2017)	Review article		*				This review shows that the time spent on digital technology can have both positive and negative effects on child well-being, depending on the activity and how much time is spent. The finding that screen-based activity and physical activity seem to be independent behaviours is particularly important for health promotion policies and should be underlined
11	Kelly et al. (2016)	Research article					*	Amblyopia is the leading cause of monocular visual impairment in children that can be treated by patching the fellow eye to force the use of the amblyopic eye. A binocular iPad game was effective in treating childhood amblyopia and was more efficacious than patching at the 2-week visit. Binocular games that rebalance contrast to overcome suppression are a promising additional option for treating amblyopia
12	Kenney and Gortmaker (2017)	Research article		*		*		Using smartphones, tablets, computers, and video games are associated with several obesity risk factors and inadequate sleep time. Although further study is needed, families should be encouraged to limit both TV viewing and newer screen devices
13	Marker et al. (2019)	Review with meta-analysis		*				The assumption of a strong association between video game playing and body mass index is small and primarily observed among adults without significant association for samples of children or adolescents
14	Nolin et al. (2016)	Research article	*					ClinicaVR analysis shows that the most common cybersickness experienced were “eyestrain” and “fatigue”. The least frequent cybersickness was “nausea” and “burping”. In addition, participants reported little cybersickness in general
15	Oliveira et al. (2020)	Review with meta-analysis		*				The review identified that AVGs were better than minimal intervention in reducing BMI and body weight, but not for increasing physical activity in young people
16	Park et al. (2017)	Research article	*					The purpose of this study was to investigate the effect of performing an oculomotor exercise, immediately before watching VR content on HMD, on cybersickness. The proposed method resulted in a significant reduction in cybersickness and therefore, the proposed method was effective in alleviating cybersickness
17	Ramírez-Granizo et al. (2020)	Review article		*				The review on the relationship between active video games and physical activity showed how active video games are an innovative element to encourage physical activity at an early age as long as they are complemented by frequent or intense sports activities. It also highlights the importance of promoting healthy lifestyles to combat sedentariness and obesity, diabetes, cholesterol, or cardiovascular problems
18	Rebenitsch and Owen (2016)	Review article	*					With VR systems becoming readily available to the general public, reports of cybersickness have increased and there is a growing concern about the safety of these systems. There is a consistent trend that the incidence of cybersickness increases from desktop to large screen to HMD, but the difference between a large screen and HMD is small
19	Rechichi et al. (2017)	Research article					*	Asthenopia (especially headache, eyelid tic, transient diplopia, and dizziness), absence of fine stereopsis, and refractive errors were statistically more frequent (mainly in the dominant eye) in children in the video game group. It is important to recognize these signs as possible functional disorders to avoid erroneous diagnostic and therapeutic interventions
20	Reid Chassiakos et al. (2016)	Review article		*		*		Risks of digital media usage include negative health effects on sleep and a higher incidence of obesity
21	Roettl and Terlutter (2018)	Research article	*					The authors analysed how an identical video game that is either played in a 2D, stereoscopic 3D or Head-Mounted-Display (HMD) VR version is experienced by the players, and how brands that are placed in the video game are affected. Subjects reported higher levels of dizziness and motion-sickness in the VR game than in the 3D and in the 2D game
22	Tate et al. (2013)	Research article		*				High levels of interactive media use such as internet surfing and video games have been specifically associated with BMI and body fat percentage in adolescent girls. The effect of screen time on adiposity may be moderated by the content of the media. This study discusses challenges with using mHealth strategies for childhood obesity prevention
23	Tosini et al. (2016)	Review article				*	*	In this review, the authors summarized the current knowledge of the effects of blue light on the regulation of physiologic functions and blue light exposure on ocular health. The accumulating experimental evidence has indicated that exposure to blue light can affect many physiologic functions, and it can be used to treat circadian and sleep dysfunctions. However, blue light can also induce photoreceptor damage
24	Turel et al. (2016)	Research article		*		*		Video game addiction can be associated with increased sleep curtailment which in turn can be associated with elevated abdominal adiposity and its resultant cardio-metabolic impairments
25	Turel et al. (2017)	Research article		*		*		Videogame play duration in the 4-h window before bedtime, typical videogame session duration, sweet drinks consumption while playing video games and poor sleep quality have aversive associations with abdominal adiposity. This study aims to untangle associations between videogame-use attributes and obesity as a first step towards identifying and examining possible interventions
26	Tychsen and Foeller (2020)	Research article	*				*	This study assessed the safety of VR 3D headset in terms of eye discomfort, head/neck discomfort, fatigue and motion sickness. Young children tolerate fully immersive 3D virtual reality game play using HMDs without noteworthy effects on visuomotor functions. VR play did not induce significant post-VR postural instability or maladaptation of the vestibulo-ocular reflex
27	Wang et al. (2020)	Review article					*	Longer smartphone use may increase the likelihood of ocular symptoms, including myopia, asthenopia, and ocular surface disease, especially in children. Thus, regulating use time and restricting the prolonged use of smartphones may prevent ocular and visual symptoms
28	Wong et al. (2020)	Review article					*	Increased digital screen time, near work, and limited outdoor activities were found to be associated with the onset and progression of myopia. The effect of near work on myopia development appeared to be related only to reading but not watching television, playing computer games, or even studying