Burn-In

Burn-in is the permanent retention of a static image — a HUD, a menu bar — on an OLED panel after very long cumulative exposure, caused by uneven pixel wear. On handhelds it is a long-tail risk, not a short-term one: it takes many hours of the same static element, and modern panels and software mitigations push it further out. It is a reason to weigh OLED versus LCD by how you will use the device, not a reason to avoid OLED — but it is real, and LCDs do not have it.