Backlight Bleed vs. IPS Glow

Put a brand new LCD monitor on a full black screen in a dark room and it will almost never look perfectly black. That alarms a lot of people into returning a perfectly healthy panel, because two different effects are at work and only one of them is a fault.

What backlight bleed is

An LCD panel does not make its own light. A backlight shines constantly from behind, and the liquid crystal layer blocks it to produce black. Where the panel is clamped slightly unevenly in its frame, light escapes around the seal — usually as bright streaks or blotches at the edges, or as a pool in one corner. That escaping light is backlight bleed. It is a physical assembly flaw, it stays in the same spot no matter where you sit, and severe cases are a legitimate reason to return a display.

What IPS glow is

IPS glow is a characteristic of the panel technology, not a defect. On IPS screens the liquid crystals cannot block light perfectly when you view them off-axis, so dark areas take on a pale silvery sheen that is strongest in the corners nearest your eyes. Every IPS panel does this to some degree, including expensive ones. VA panels show far less of it but trade away viewing angles; OLED shows none at all because unlit pixels emit nothing.

How to tell them apart

Move your head. IPS glow shifts, fades, or migrates to a different corner as your viewing angle changes, and it largely disappears when you look at the screen dead center from a distance. Backlight bleed is fixed — the same streak stays in the same place from every angle, because it is light physically escaping the panel edge. Test in a dark room with screen brightness at your normal setting, and step back a little: at arm's length most glow vanishes while bleed remains. Use the Backlight Bleed Check for a true full-screen black to judge against.

How much is normal

Some unevenness on any LCD is expected, and a pitch-black room at maximum brightness exaggerates it well beyond anything you would notice in real use. The practical standard is whether you can see it while actually using the screen: if letterboxed film bars, dark game scenes, or a dark-mode editor show visible patches at normal brightness, that is worth acting on. If it only appears on a deliberate black test pattern with the lights off, most panels look like that. Manufacturers rarely list a bleed threshold the way they publish pixel counts, so it is typically handled under general return policies rather than the pixel rules in the manufacturer policy comparison — which makes the return window the deadline that matters.

Bleed and glow are both whole-area effects. A single bright dot on a black screen is something else entirely — run the full test tool and compare against dead, stuck, and hot pixels.