Updated 20-Sep-2023
It turns out that there are many legitimate concerns when it comes to virtual reality and children, the ones that are different than the concerns with video games (addiction, etc.), are around how the eyes focus (or not) in virtual reality as opposed to reality. Currently, one could say that all virtual reality devices and programs are built for adults.
VR AR MR XR
VR, AR, MR, and XR terms define how much virtual and how much of the real world are provided and how they interact. Merged reality (MR) is where virtual objects interact with the real world, and/or real world objects interact in a virtual world. This is definitely more immersive and seamless than augmented reality, which is more or less information overlays on top of the real world. VR is essentially a separate world, but the blurring of lines in Mixed Reality (or rather XR as the entire gamut of reality and virtuality.