You turn the lights off, start a film, and the bottom corner of the screen is sitting there faintly lit. During the day, working on documents, you never saw it. Most people spend the rest of the return window unsure whether that counts as a fault.
Where the dead pixel guide deals with a single point, this one deals with whether the whole surface lights evenly. Different axis. A dead pixel is there or it isn’t; uneven brightness is always a matter of degree, so “yes or no” never quite answers it.
Backlight bleed, IPS glow, and mura are three different things
They have different causes, and one of the three is not a fault at all.
Backlight bleed is light escaping through the gap between the panel edge and the frame. On a black screen you see specific bright patches at the corners or along an edge. It stays put when you move your head, and it sits in the same place every time. It comes from assembly tolerance and panel pressure, so it varies a lot between individual units.
IPS glow is a viewing-angle property of IPS panels. Look from an angle and the corner nearest you washes out to a silvery gray. Move your head and the bright area moves with you. From dead center it fades or disappears. Every IPS panel has it to some degree. It is not a fault.
Mura, or clouding shows up on bright screens instead. A gray background looks patchy, like thin cloud, or one corner runs yellow or blue. The tell is that you see it on gray and white, not on black.
The distinction matters because if you exchange a unit over IPS glow, the replacement has it too. People who go through three exchanges and give up usually got stuck here.
| Visible on | Moving your head | A fault? | |
|---|---|---|---|
| Backlight bleed | Black screen | Stays put | Depends on degree |
| IPS glow | Black screen | Follows you | No |
| Mura / clouding | Gray, white screen | Stays put | Depends on degree |
On OLED, the first two don’t apply
Bleed and IPS glow are properties of an LCD, which has a backlight behind the panel. OLED pixels emit their own light and there is no lamp behind them, so on a black screen the pixels simply switch off. There is no light to leak.
If something lifts on a black OLED screen, look elsewhere: a reflection, the banding that shows up at very low brightness, or image retention and burn-in. Burn-in runs the other way, being an OLED phenomenon that LCDs largely don’t get. Mura is the one that appears on both.
Your product’s spec sheet tells you which you have: IPS, VA, and TN are LCD; OLED and AMOLED are not.
The conditions decide the result
Open the dead pixel test above and it fills the screen with black and with gray. Same screens as the pixel check, but this time you are looking at the surface rather than for a point.
Get the conditions wrong and you will miss what is there, or see what isn’t.
Darken the room. With lights on, the room reflects off the panel and you cannot separate reflection from bleed.
Give your eyes a minute or two. A black screen viewed right after walking into a dark room looks more even than it is.
Use the brightness you normally use. Wind it to maximum and every panel bleeds. The question is not whether it leaks at full brightness. It is whether it bothers you at the brightness you actually work at.
Look once straight on, once from an angle. Those two looks are what rule out IPS glow.
Your photograph exaggerates it
This is where judgement usually goes wrong.
Photograph a black screen in a dark room and the camera raises its own exposure. What your eye reads as a faint lift comes out looking like a torch. Most of the “is this bad?” photos posted online are in that state.
It cuts the other way too. Send that photo to a retailer and they read it as exaggeration, which means the genuinely severe cases get the same reception.
If you want a photo, turn off auto exposure and shoot it close to what your eye sees. On a phone, press and hold to lock focus, then drag the exposure slider down. If that is awkward, notes beat a misleading picture:
- Which area — quarter the screen; “bottom left corner” is specific enough
- At what brightness — your normal setting, or only at maximum
- What happens when you move — if it follows you, it is IPS glow
- When it bothers you — “the area beside the subtitles lifts during dark scenes”
That last one carries the most weight. Describing the use case works better than arguing about degree.
There is a standard. It just isn’t in your warranty
The usual line is that bleed has no standard. That isn’t quite right.
The international standard carries a number. ISO 9241-303, the ergonomics standard for electronic visual displays, covers luminance uniformity and asks that the difference across the screen not exceed 1.7:1.
Some products are sold on uniformity and guarantee it. EIZO ColorEdge monitors ship with an individual adjustment report giving the color difference (ΔE00) and luminance ratio (ΔLR) measured at 25 points across the screen. In color-critical monitors uniformity is a selling point, so it gets a figure.
The gap is elsewhere. Consumer laptop and monitor warranties mostly say nothing about how much bleed is acceptable. The same document that sets a pixel count for dead pixels leaves luminance uniformity out entirely. Not for want of a standard, but because that product isn’t warranted against it.
So in practice it splits like this.
Inside the return window, there is nothing to argue about. The window usually covers change of mind, so “is this within spec” is not the question. Checking in time is the whole answer (return rights).
Once the window closes, the judgement is theirs. A service center compares your unit against others and decides, and “they all look like that” is a real possible outcome. Often it is even true.
Forum claims about how much bleed qualifies for an exchange are weak for that reason. If the figure isn’t in the warranty for the product you bought, the claim is just what one person heard from one agent. The two documents that decide it are your product’s warranty terms and your retailer’s return policy.
Buying used
Bleed hides especially well in a used sale. Seller photos are of bright screens, and you usually meet somewhere brightly lit.
If you can see the machine in person, put a black screen up and cup your hands around part of the display to shade it. It is not thorough, but a badly affected panel shows itself even under that. Pair this with the used laptop checklist.
In short
View a black screen and a gray screen in a dark room, then look again from an angle. If the brightness follows your head it is IPS glow and not a fault. If it stays put it is bleed. If the degree bothers you, checking whether your return window is still open gets you further than hunting for a threshold.
For point defects on the same screens see the dead pixel guide, and for a pattern that stays on screen see image retention and burn-in.