Backlight Bleed vs. IPS Glow vs. Clouding
Three different things that all look like 'uneven light near the edges of a dark screen' — but only one is usually a defect.
Fill your screen with black and you'll almost always see something — some unevenness near the edges or corners. It's rarely nothing, but it's also rarely as bad as it looks in a dark room. Here's how to tell which one you're actually looking at.
IPS glow
If you have an IPS panel and you see a soft, hazy glow in one or two corners that changes intensity or shifts position as you move your head or viewing angle, that's IPS glow. It's a normal characteristic of IPS LCD technology, not a defect — it happens because IPS panels don't produce true blacks and the effect is most visible at off-axis viewing angles in a dark room. Every IPS monitor has some amount of it. It is not something a return will fix, because the replacement unit will have it too.
Backlight bleed
Backlight bleed is light leaking through the LCD layer around the edges of the panel, usually most visible along the bottom or one side. The key difference from IPS glow: bleed does not move or change when you shift your viewing angle — it's coming from a physical gap or pressure point in the panel assembly, not from the display technology itself. Run the backlight bleed test, sit dead-center, and look for a sharply-defined bright patch that stays put. Some minor bleed is normal on nearly every LCD; a bright patch visible in normal room lighting is worth returning over.
Clouding (mura)
Clouding — sometimes called mura — is uneven, cloud-shaped patches of brightness across a grey field rather than black, most common on VA panels. It's a manufacturing variance in the panel's backlight uniformity. Use the uniformity test on a mid-grey field, not black, to check for it — clouding is often invisible on a pure black test but obvious on grey.
The practical test
Run all three: black in a dark room for bleed and glow (move your head to tell them apart), then grey for clouding. If what you see moves with your viewing angle, it's glow — normal. If it stays fixed and is bright enough to be visible in a normally-lit room, it's worth acting on.