For parents worried about their children playing 3D virtual reality games, a study in the American Journal of Ophthalmology offers some reassurance. The investigation found no noteworthy negative visual-motor side effects in kids between the ages of four and 10 who played the games.

Even though product safety warnings on VR headsets ban their use in children under 13, they are already popular with younger kids. Researchers from the St. Louis Children’s Hospital at Washington University Medical Center reported children who played these games had no significant balance issues or vestibular-ocular reflex adaption problems. In fact, the study noted discomfort and after-effects generally associated with the games may be less likely in children than adults.

The study used recordings from 50 children aged four to 10 who used a Sony PlayStation virtual reality headset for two 30-minute sessions. The activity included a first-person 3D flying game that required head movement to control flight direction.

After each session, researchers performed testing for binocular corrected distance visual acuity, refractive error, strabismus, steroacuity and imbalance. They also looked for any visually induced motion sickness via a questionnaire the children filled out. The study also tested visual vestibulo-ocular reflex adaption pre- and post-game play in five of the children.

Investigators noted the minimum binocular corrected distance visual acuity was 20/50 (logMAR 0.4) and stereoacuity was 800 arc sec or better.

Researchers found 46 of the 50 children (94%) completed both virtual reality play sessions with no significant change from baseline in binocular corrected distance visual acuity, refractive error, binocular eye alignment or stereoacuity. Also of note: postural stability degraded on average just nine percent from baseline after 60 minutes of play.

Simulator sickness scores only increased by 4.7% for each of the four symptom categories: eye discomfort, head/neck discomfort, fatigue and motion sickness. Also, of the five children tested in the subset study, their visual vestibulo-ocular reflex gain remained unchanged.

As for the study dropout, three children (two girls and one boy, 6%) discontinued the trial during the first 10 minutes. Both girls (between the ages of five and six) reported mild motion sickness, and the boy said he was “bored” and complained the headset was uncomfortable.

The investigators said no child had after-effects in the days following the virtual reality game play.