There is a particular kind of headache that only happens in poorly designed VR interfaces. It comes from staring at a menu panel positioned 0.3 metres from the player's face. Most students discover this problem only after someone else wears their headset, because the designer has adapted to their own mistake.
The Starting Design
Before: A student ports a flat 2D HUD directly into VR space, anchoring it to the camera at close range. Every number, button, and health bar sits at a depth of roughly 30 to 50 centimetres. This creates vergence-accommodation conflict, the optical mismatch where your eyes converge at one distance but the lens focuses at another. After five minutes, players report tired eyes and blurred text edges.
The Rebuilt Approach
After: The same information is repositioned at 1.5 to 2 metres, attached to a diegetic surface like a wristband or a panel on the environment wall rather than the camera. Text size is scaled to remain readable at that distance. The headache reports disappear. Players describe the interface as feeling natural, which is exactly how good VR UI should feel.
Diegetic UI is not just an aesthetic preference. It matches where human eyes are physically comfortable focusing during extended wear. Students who learn this distinction early stop treating VR as a screen and start treating it as a physical space with optical constraints that cannot be ignored.