I ask because my son is doing vision therapy and I asked if he could play a VR system. They said it would be ok for him if the system uses Optical Infinity. I believe it has to do with the headset and how the eyes adjust to the pictures.
This turns out to be a rather complex question - you can get into a real rabbit hole trying to research this. In a mathmatical sense, the lens focus at infinity but in real-world practice alot of people report that the focal distance is equivalent ~1.4-3m depending on the HMD and their testing methodology. We don't really publish a focal distance because it's not a super cut and dry number due to how human preception works.
For instance, I'm nearsighted and see distance better in the HMD than in real-life so it certainly isn't focusing at infinity. If I alter the distance the lenses are from my eyes, I start to replicate what my vision is like IRL.
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The best bet would be for him to try a VR headset and see how well he can see, and if he sees fine in a particular brand of headset, get THAT headset since from my experience with multiple VR headsets, each one of them has different lens qualities for MY eyes. Some I can see fine without using my eye glasses, others not so much. Good luck and hope you find what you are looking for.