Why a ghost appears
Every OLED pixel gets a little dimmer as it's used. The brighter and hotter it runs, the faster it ages. When the same shape stays on screen for a long time, the pixels under that shape age faster than their neighbors, and the shape shows up as a faint ghost on a flat gray or white screen. Static content is the main risk, since it keeps the same pixels at the same brightness: a taskbar, a menu bar, a game HUD, a channel logo.
Blue emitters wear fastest, and makers size the blue subpixel larger to even it out. LCDs are rarely affected, and when an LCD does hold a ghost, it's usually transient.
Burn-in or image retention
Not every ghost is burn-in. Image retention is temporary. You see a faint outline of a recent static image, and it fades within minutes or after a pixel refresh. Burn-in doesn't fade.
So the test is time. Show a flat gray fill, like the one in the Monitor Test, then run the pixel refresh from the menu or let the screen rest, and look again. A ghost that's still there is wear. The fill makes a ghost easier to see, but it can't tell the two apart on its own.
Near-black blotches or banding that were there from day one aren't burn-in either. Wear builds up over time, so it can't be there on day one.
What cuts the risk
Wear can't be stopped, but a few habits and settings slow it down:
- Let the screen run its pixel refresh or compensation cycles, and don't cut the power as soon as you stop using it.
- Keep pixel shift on. It moves the image a pixel or two now and then, so no hard edge sits on the same pixels forever.
- Use dimming of static content, like logo or taskbar dimming. If part of the picture dims after a while, that's the screen protecting itself, not a fault.
- Auto hide the taskbar, use dark themes and let the screen sleep when you step away.
- Don't run the screen brighter than the room needs. Heat is one of the main causes of wear.
- Mix up your content. Fixed layouts for many hours a day are the case that wears a screen unevenly.
Check the warranty
Whether a warranty covers burn-in depends on the maker and the model, so read the terms for the exact model before you buy. If you plan to use an OLED for static work, like spreadsheets or a fixed trading layout, get the answer in writing.