It's also possible that they are different from you (e.g. they have an IPD that's not in the range the headsets are designed for, or they are more sensitive to

It's also possible that they are different from you (e.g. they have an IPD that's not in the range the headsets are designed for, or they are more sensitive to the vergence-accomodation-conflict) and still experience eye strain/headaches. I do own a headset and I also love beat saber and alyx, but I can't use it for too long.