I totally agree! I feel like I am scuba diving or snorkeling. The discomfort drains you.

Just thinking about the extra work your brain is doing to process VR visuals

Universal issues: * flat, everything in focus rendering instead of "light field" style, per-eye adjusted display focal depth

Per-individual issues: * Mis-aligned pupils (IPD) * User not having glasses or corrective lenses inside the headset * Wrong prescription (Everything is 4 - 6 feet from the user's perspective for a prescription), so bifocals or the wrong pair of prescription glasses create fatigue * Motion sickness sensitivity

Doing a little VR can consistently build up tolerance, but there is always some amount of overhead for me that is fatigue inducing.